John Stuart Mill on the Suez Canal and the limits of self-defence

Abstract

Michael Walzer's use of John Stuart Mill's A Few Words on Non-Intervention (1859) helped to inaugurate it as a canonical text of international theory. However, Walzer's use of the text was highly selective because he viewed the first half as a historically parochial discussion of British foreign policy, and his interest in the second was restricted to the passages in which Mill proposes principles of international morality to govern foreign military interventions to protect third parties. As a result, theorists tend to see those canonized passages as if through a glass darkly. Attention to the detail and context of Mill's first-half critique of Lord Palmerston's opposition to the Suez Canal project reveals that his discussion of purely protective intervention is embedded in a broader exploration of the limits of self-defence, including the moral permissibility of preventive military force and the use of protective interventions for defensive purposes. Moreover, reading the text holistically facilitates a refutation of some objections directed at it by Michael Doyle to the effect that Mill's conception of self-defence incorporates elements of aggression which makes it extremely dangerous when adapted for application to the contemporary world.

I look with apprehension to the uncertainty of the future as regards France – a future which any statesman is bound to consider from the darkest side…

John Henry Temple, 3rd Viscount Palmerston (1784–1865)¹

Thus Europe saw, in the first transaction of this reign [of Elizabeth I], the genius and capacity of the queen and her ministers. She discerned at a distance the danger, which threatened her, and instantly took vigorous measures to prevent it.

David Hume (1711–76)²

Georgios Varouxakis observes that John Stuart Mill (1806–73):

now has a prominent place in anthologies of political thought on international relations or international ethics. In recent years, he has been accorded the status of one of the ‘leading international thinkers’, who are set apart by ‘the fact that their thought retains its intellectual force long after it was written down and the events that provoked it have faded into history’. In other words, […] Mill has been ‘canonised’ in the emerging literature of ‘international political theory’.³

One important example of Mill's perceived contemporary relevance for international theory is how some liberal nationalists still appeal to his defence of mononational states in Considerations on Representative Government (1861).⁴ However, it is Mill's A Few Words on Non-Intervention, originally published in Fraser's Magazine in December 1859, that is usually anthologized.⁵ Furthermore, the extracts selected, from the second half of the text, seem to reflect the principal reason for Mill's canonization: its use by one of the 20^th century's most important just war theorists, Michael Walzer.⁶

To illustrate, when the editors of one anthology summarize Mill's most important claims, they highlight those ‘re-employed’ by ‘Walzer’:

non-intervention is generally the right policy because it is not possible for outsiders to create free states; peoples have to take freedom for themselves, they cannot be given it, and the exceptions to this rule largely concern circumstances where intervention would be, in effect, counter-intervention – action taken in order to counter the prior intervention of an oppressing power.⁷

However, explaining their selection of authors and works, they also insist that:

[although] [t]he writers represented in this collection can be made to address contemporary debates in International Relations theory, […] they have to be understood in their own terms and their own context before they can be turned into our contemporaries. Our aim in this collection is, as far as is possible, to allow the authors we select to speak for themselves rather than to respond to our agenda.⁸

Thus, in the case of Mill, they provide context for the passages selected,⁹ and note Walzer's eschewal¹⁰ of Mill's qualification that different norms may be needed when dealing with ‘barbarians’.¹¹ Nevertheless, without challenging the editors' view that the second half of Non-Intervention is more important, this paper will demonstrate the difficulty of allowing Mill to speak for himself while abstracting away from the first.

Troubled that ‘the most influential treatment’ of ‘Mill's [international] theory’ was based on ‘the perusal of the latter (shorter) part of one short article’,¹² Varouxakis' seminal contextualist studies trace the development of Mill's views across a range of writings, interpreting them in light of the political events and intellectual exchanges that prompted their creation.¹³ However, even Varouxakis says comparatively little about Non-Intervention's first-half discussion of a contemporaneous foreign policy controversy, concerning Britain's response to Egypt's decision to allow a canal to be built linking the Mediterranean to its Red Sea port of Suez. Moreover, I will argue that this omission is important for international theorists whose principal interest remains the passages on protective intervention canonized by Walzer. By attending to that discussion in detail and context, I will show how the canonized passages are embedded in an even more important message about the moral limits of self-defence, including what we now call preventive warfare.

In what follows, the first section explains why Mill's On Liberty, published in February 1859, treats both self-defence and protection of others as potential justifications for the resort to force and coercion, but may inadvertently encourage readers to ignore Non-Intervention's discussion of the Suez Canal project. The second section shows why the contemporaneous Prime Minister, Lord Palmerston, believed that the project threatened Britain's security, and examines a parliamentary debate in which Palmerston was fiercely criticized for opposing it by John Roebuck MP. This opens the door for the third and fourth sections to illustrate how Mill adapts Roebuck's analysis of both the strategic significance of the canal, and the immorality of Palmerston's opposition to it. With these contextual foundations laid, the fifth and sixth sections show that Mill's moral analysis only rules out a precautionary subcategory of preventive defensive warfare, and explain this limitation with reference to two of his historical case studies: (i) Russia's intervention in Hungary in 1849 and (ii) the interventions of Elizabeth I. Finally, the seventh section shows why my interpretation undermines some claims made by Michael Doyle – who has recently built on Walzer's legacy by developing a neo-Millian guide to protective intervention in the contemporary world¹⁴ – concerning the ethical implications of (ii) for defensive interventions in the present.

Reading Non-Intervention holistically

Mill begins Non-Intervention by asserting that, although Britain is unusually benign for a great power, several factors make people ‘on the Continent’ view it as selfish and ruthless. One of the most important is that the ‘habitual expressions’ of certain ‘English statesmen’, to the effect that Britain should adhere to a policy of non-intervention unless its ‘interests’ are at stake, represent ‘ourselves as worse than we are’. According to Mill, what most of these statesmen mean is that Britain should (1) only consider intervention if its own ‘security’ is threatened; and hence (2) refrain from intervention for altruistic purposes: for the good of other peoples or countries alone. Consequently, Mill insists that continental critics are mistaken to interpret these statesmen as endorsing imperious ‘aggrandizement’ at other countries' expense.¹⁵

Another important factor is that, partly due to the said statesmen's ‘sins of speech’, when it comes to Britain's ‘deeds’, continental critics often focus less on ‘our ordinary course’ than on the ‘exceptions’ thereto, ‘regard[ing] these as the real index to the purposes within’.¹⁶ The major negative exception Mill highlights is Palmerston's Suez policy, to be examined below. As will become clear, Mill's major concern is that if the French people judge Palmerston's policy as representative of Britain's ordinary course, they may conclude that war with Britain is not only inevitable but just.

Although Mill's discussion of these issues takes up the first half of Non-Intervention,¹⁷ theorists tend to neglect it because they assume that he discusses matters of greater import in the second half of the text. For example, summing up his approach in a philosophical commentary, Walzer sets aside ‘the first part’ because it ‘deals more narrowly with British foreign policy and is not of interest here’.¹⁸ One possible rationale for this stems from Mill's claim that, although prompted to write Non-Intervention by contemporaneous events, he also ‘took the opportunity of expressing ideas […] respecting the true principles of international morality’.¹⁹ Some may infer that the discussion of Palmerston's policy is both logically and sequentially distinct from his discussion of the said principles – that the text begins with the historically parochial before ascending to a higher plane of perennial politico-philosophical significance. If this were true, theorists might ignore the former discussion but still grasp Mill's principles of international morality.

This view could also be reinforced by a certain conception of Non-Intervention's relationship to Liberty, in which Mill presents an oft-named Harm Principle to guide the ethics of compelling or controlling adults of sound mind:

the sole end for which mankind are warranted, individually or collectively, in interfering with the liberty of action of any of their number, is self-protection. That the only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others. His own good, either physical or moral, is not a sufficient warrant.²⁰

Broken down analytically, it follows that if one individual or group is justified in interfering in the life or lives of another, the purpose of the former's interference must be at least one of the following: (1) self-defence against non-consensual harm (the defence clause); (2) protection of a third-party individual or group against the same (the protection clause); or (3) the paternalistic promotion of the interests of an individual or group whose consent is unnecessary because they are not members of, or do not constitute, a civilized community (the civilization clause).²¹ Since the satisfaction of one of these clauses is merely necessary to justify force or coercion, the Harm Principle provides a framework for the application of rules of narrower scope specifying when there is sufficient reason to resort to them.²²

Although the Harm Principle has three clauses, Liberty focuses on interference in civilized communities, and usually frames this in terms of ‘society’ interfering in the life of one person to ‘prevent harm to others’.²³ Similarly, most of the second half of Non-Intervention focuses on the ethics of a government of one civilized community interfering militarily in the affairs of another, with Mill's key examples involving the protection of third parties.²⁴ Thus, by priming readers to focus on the philosophical puzzles raised by intra-societal applications of the protection clause, Liberty may also prime them to assume that the philosophical content of Non-Intervention is exhausted by its second-half examination of the application of that clause to the international domain.

One welcome sign that this assumption is being challenged is the burgeoning literature on Non-Intervention's mid-text discussion of British rule in India, including the role that the civilization clause plays in Mill's views on the ethics of imperialism, colonialism, and empire.²⁵ However, the role of the defence clause in Mill's ethics of international affairs remains relatively neglected. For example, some scholars of Mill on foreign military intervention, such as Joseph Miller,²⁶ Alexis Heraclides, and Ada Dialla,²⁷ set aside his discussion of defensive justifications entirely. Others, such as Varouxakis²⁸ and Doyle,²⁹ acknowledge that Mill allows for foreign military intervention to be justified in defensive as well as protective terms but without attending to Mill's discussion of Palmerston's Suez policy in much detail in the process.

Nevertheless, by emphasizing the importance of defence to Mill, the interpretive approach adopted here overlaps with that of Varouxakis³⁰ in another respect: his observation that Mill's discussions of international affairs invoke the language of his ‘Art of Life’. This Art guides ‘the promotion of happiness’ – Mill's ultimate utilitarian end – by integrating the norms or rules of three domains: ‘Morality’ or ‘the Right’ (the avoidance of wrongdoing); ‘Aesthetics’, including ‘Nobility’ (what is worthy of admiration); and ‘Prudence’ or ‘the Expedient’ (effective alignment of means and ends, especially but not exclusively to promote self-interest).³¹ As we will see, Mill's principles of international morality allow scope for prudence narrowly construed, by allowing for effective self-defence, and limiting one nation's obligations to sacrifice itself for another. However, they also preclude its descent into unconscionably harmful forms of selfishness, while leaving scope for its conception of self-interest to broaden in an ennobling ascent.³² In that regard, they echo a dictum of Vattel, who Mill acknowledges reading:³³ that ‘Prudence is a duty incumbent on all men’, especially ‘heads of nations’, but ‘justice’ is still ‘inseparable from sound policy.’³⁴ Although Liberty's focus on intra-societal applications of the Harm Principle may lead readers to overlook its salience to the interaction of individual members of ‘mankind’ as such,³⁵ and thus any aggregated groupings thereof, it needs that breadth of scope to serve as a fundamental principle of morality within his Art. Indeed, Mill offers no example of just international force or coercion that violates it.

Palmerston and Roebuck on the Suez Canal project

By claiming that most of the more cynical-sounding British statesmen are focused on security, Mill implies that their foreign policy ethics are based on a narrow version of the Harm Principle allowing force and coercion to be justified via the defence clause alone. Although Mill considers this morally and nobly deficient (fifth section below), he opposes exaggerating the deficiency because universal adherence to the defence clause would produce international peace provided it is properly understood.³⁶ This raises the question of why Palmerston might have considered the use of force or coercion in Egypt for the sake of self-defence, the answer to which can be traced back to Napoleon I.

Between 1798 and 1801, Napoleon invaded and occupied Ottoman Egypt and Syria, and formed tentative plans with Emperor Paul of Russia to invade British India overland via Persia and Afghanistan.³⁷ Both the Franco–Russian alliance and Napoleon's occupation of the said Ottoman territories were short-lived. However, Napoleon was thought to have envisaged reoccupying Egypt, and establishing a naval base, to facilitate a direct attack on British India via the Red Sea.³⁸ Between 1831–33 and 1839–41, the renegade viceroy of Egypt, Muhammad Ali Pasha (r. 1805–48), twice rebelled and warred against the Ottoman Sultan. Moreover, he was only prevented from marching on Constantinople through intervention by Britain and other foreign powers. In both cases, the British intervention was orchestrated by Palmerston, then Foreign Secretary, who feared that Ali's revolts would result in Turkey falling into Russian hands.³⁹ France joined Britain in the first intervention but encouraged Ali in the second, thus triggering the Near East Crisis in which the danger of war arose between Europe's two most powerful constitutional monarchies.⁴⁰ However, ultimately, France was coerced into a humiliating climbdown by a British-led alliance, which battered Ali into abandoning his bid for independence and imperial expansion in return for the right to rule Egypt on a hereditary basis.⁴¹

Although that ended Ali's revolts, as his successors expanded their commercial and diplomatic ties with France through the 1840s and 1850s, and Louis-Napoléon Bonaparte seized power in France in 1851, Palmerston increasingly feared a conspiracy against Britain. As he put it in a private letter in December 1859:

It has been deemed by all English statesmen that the possession of Egypt by France would be injurious to England, and the like opinion has always been entertained by French rulers, from the First Napoleon to the Third. The French, therefore, have always tried to separate Egypt from Turkey, as a first step towards making it French. We, on the contrary, have always endeavoured to maintain the connection of Egypt with Turkey, in order to prevent Egypt from becoming French.⁴²

Indeed, for reasons to be specified below, as early as 1851, Palmerston observed that an attempt to build the canal could lead to a Franco–British war ‘for possession of Egypt’.⁴³

In November 1854, it was thus of great strategic moment when Ali's fourth son, Muhammed Said Pasha (r. 1854–63), granted a concession to start building the canal to a French entrepreneur, Ferdinand de Lesseps. Although France was then allied with Britain to protect Ottoman Turkey against Russia in the Crimean War (1853–56), the fact that Lesseps was a former French diplomat made the commercial venture appear like a government-backed project. Moreover, the crowing of hardline French nationalists, such as the politician and journalist Émile de Girardin, who gloated that the canal constituted ‘the defect in the British cuirass’,⁴⁴ reinforced Palmerston's fear that the project was undertaken with aggressive intent.⁴⁵

Consequently, during his first premiership (1855–58), Palmerston sought to persuade, if not coerce, the Ottoman Sultan Abdulmejid I (r. 1839–61) – over whom Britain held leverage as his protector in the Crimean War – to veto the Pasha's decision.⁴⁶ Lesseps responded by touring Europe, including Britain, attempting to drum up commercial and popular support for his venture by portraying it as an idealistic attempt to unite East and West through trade.⁴⁷ Indeed, within Britain, his supporters included the East India Company, Mill's employer before its nationalization in 1858.⁴⁸ There was also an initial parliamentary debate about the project in July 1857 in which Palmerston insisted that, although he deemed it an unviable ‘bubble scheme’, his goal was to defend the ‘country’ against ‘hostility’ to its ‘interests’ rather than to save ‘gullible capitalists’ from self-harming folly.⁴⁹ Palmerston thereby avoided justifying his policy on paternalistic grounds for which Mill's civilization clause lacked scope. Moreover, he helped to ensure that the second parliamentary debate on the issue in June 1858, following the fall of the Palmerston Ministry for independent reasons months earlier, focused upon the nature of Britain's interests vis-à-vis the project, on the one hand, and what could count as defending them, on the other.

This debate was called by John Roebuck, a utilitarian Radical with whom Mill had been friends as a young man but was by then estranged.⁵⁰ Condemning Palmerston's policy, Roebuck proposed the resolution that ‘England’ not use its ‘power and influence’ to ‘induce the Sultan to withhold his consent’.⁵¹ On the question of Britain's interests, Roebuck claimed it would benefit commercially from canal-facilitated trade,⁵² and dismissed the concern that ‘this canal might be the means of [France] separating Egypt from Turkey’, as it would actually have a unifying effect.⁵³ Moreover, he also rejected opposition to the canal based on the worry that if the French navy became ‘superior in the Mediterranean’, the canal would facilitate an invasion of India. If the French achieved superiority, he reasoned, they could go ‘round the Cape of Good Hope’ anyway, whereas if Britain retained superiority, a French attack through the canal would leave its ships caught ‘like rats in a trap’ in the Red Sea.⁵⁴

Roebuck also made a point, ascending into ethical theory, that Mill would navigate in Non-Intervention: since a canal facilitating transport around the world ‘was for the benefit of mankind’, by declaring it hostile to his country's interests, Palmerston ignobly implied that the ‘interest of England’ was at odds with ‘the interest of mankind’. In contrast, Roebuck declared ‘the interest of England herein’ ‘entirely identical with the interest of mankind’⁵⁵: ‘the happiness of mankind’.⁵⁶ Condemning Palmerston for sending the message to France that the British ‘were an insolent’, ‘grasping’, and ‘selfish people’, he insisted it was imperative that parliament support his resolution, and thereby send the message that Palmerston had ‘misrepresented’ the country.⁵⁷

In his reply, Palmerston suggested such ‘philanthropic reveries’ ignored key strategic considerations.⁵⁸ France could seize the canal by marching an army into Egypt from Algeria, and then use it as a moat to exclude Turkish forces. Moreover, that would give it a naval advantage, as it could attack India via the canal while forcing any British ships sent in response to take the long route around the Cape.⁵⁹ Thus, he concluded, Britain should reject such imprudent prescriptions, based on ‘a too generous wish to promote the prosperity of the human race’.⁶⁰

By framing his position thus, Palmerston declared intervention with the Sultan, albeit in a comparatively mild diplomatic form, as legitimate self-defence, and non-intervention as supererogatory self-sacrifice. This helps to explain the structure of Mill's response in Non-Intervention, which is built around two key moves. Firstly, endorsing Roebuck's key commercial and strategic claim, that the canal would not harm British interests. And secondly, insisting that even if Palmerston were right that the canal would harm British interests, accepting this would be obligatory because Palmerston's policy was not authentic self-defence.

Mill's strategic response to the parliamentary debate

At the strategic level, Mill dismisses the fear that the canal would threaten Britain's ‘Oriental possessions’ by facilitating ‘the access of foreign navies’. After all, he reasons, ‘the same thing which would facilitate the arrival of an enemy, would facilitate also that of succour’, and ‘our power of resisting an enemy does not depend upon putting a little more or less of obstacle in the way of his coming, but upon the amount of force which we are able to oppose to him when come’.⁶¹ In doing so, Mill effectively echoes Roebuck while appearing to ignore Palmerston's salient response thereto: that if France seized the canal and sent ships through it to attack British India, Britain would be unable to bring succour through it in response.

The likely explanation for this omission can be derived from a letter Mill wrote during the Second War of Italian Independence (April–July 1859). Noting that Russia might intervene on the side of France, which was supporting the Kingdom of Sardinia's attempt to expel the Austrian Empire from Italy, Mill expresses concern that the Franco–Russian coalition might so weaken Austria that they would acquire a free hand to turn on an isolated Britain. As he puts it, ‘the two together will be a match for her at sea, and vastly superior on land. It is quite possible that Europe may be divided between two great military despotisms, and freedom driven to take refuge in America and Australia’.⁶²

While dismissing Palmerston's concerns in Non-Intervention, Mill also echoes Roebuck on the prospect of ‘French fleets in Eastern seas’ by claiming that ‘if we ever became unable to defend India against them, we should assuredly have them there without the aid of any canal’.⁶³ When read in conjunction with his letter, the point generates the stronger implication that if France ever acquired naval dominance, those fleets would be able to surround Britain. At that point, the question of whether France could also use its fleet to threaten British India via the canal rather than the Cape would be more or less inconsequential, as Britain's focus would have shifted to national survival.

The preceding makes it possible to see that when Mill wrote Non-Intervention his view was that Britain's key strategic priority was to prevent the formation of a hostile Franco–Russian alliance. That meant it was important that the French not come to view Britain as its enemy, and hence important for British statesmen not to say or do things that generated that impression. Thus, Mill would have been extremely concerned that ‘[i]t is the universal belief in France that English influence at Constantinople, strenuously exerted to defeat this [canal] project, is the real and only invincible obstacle to its being carried into effect’.⁶⁴ Furthermore, Mill would have lamented the fact that, despite Roebuck's plea for Britain to signal that it did not perceive France as an adversary, the parliamentary debate concluded by rejecting his resolution.

Consequently, since Mill made the effort to ensure Non-Intervention was reviewed in France,⁶⁵ he seems to have been sending a diplomatic message of his own: that the ‘opposition to the Suez Canal’ was not a ‘national opposition’ but that of ‘individuals, mainly, it is probable, of one individual’.⁶⁶ This gave Mill little reason to delve any deeper into the strategic rationale for Palmerston's position than was necessary to render it minimally intelligible to his Franco–British audience. After all, giving serious consideration in that article to how France might perform the role of an adversary would have been to risk undermining its message that Britain did not view it as one. This is especially true since Mill's private view of how France might perform that role, given naval dominance, was even bleaker than anything Palmerston had said in his public speeches.

Kindred considerations may also explain why Mill's discussion omits any reference to one of the key strategic points made in the parliamentary debate by William Gladstone, the future Liberal Prime Minister. Dismissing Palmerston's concerns, Gladstone had asked rhetorically what ‘Power’ would ‘really possess this canal if it were opened?’, answering that it ‘would necessarily fall within the control of’ Britain, ‘the first maritime Power in Europe’.⁶⁷ In Non-Intervention, Mill chides cynically minded foreign observers of Britain who assume that its genuinely laudable and self-sacrificing opposition to slavery and the slave trade must serve ‘some peculiarly English interest’.⁶⁸ Mentioning Gladstone's point might have helped Mill to garner support for non-intervention in the canal project from a British audience, by alleviating their concerns that France could use it in the way Palmerston described. However, as the preceding quotation makes clear, doing so would have risked reinforcing Britain's negative image in France by reinforcing the view that, if it suddenly opted to do the right thing, the Perfidious Albion must be plotting to control the canal itself.

Mill's moral response to the parliamentary debate

Although Mill's second argument against meddling with the project is more straightforwardly moral, it aligns with the preceding strategic one by highlighting the imprudence of Britain harming other countries in ways that could justify them treating Britain as a hostile power. However, before examining it in detail, it is worth noting another consideration raised by the parliamentary debate of 1858: Lord Russell's observation that some believed Palmerston opposed the project because there are ‘certain ports of France and other continental countries’, ‘nearer to Egypt than England’, that ‘will gain commercial advantages over this country by the formation of a canal’.⁶⁹ Mill concurred with Russell's judgement that the canal was not a commercial threat as Britain would benefit from such competition on balance.⁷⁰ Nevertheless, it is worth explaining why Mill's position implies that Britain would lack a right to restrict such trade in the name of self-defence, even if it were certain that the canal would harm it economically.

In Liberty, Mill explains that one reason that satisfying either the defence or the protection clause is insufficient to justify the resort to force or coercion is that, in ‘many cases, an individual, in pursuing a legitimate object, necessarily and therefore legitimately causes pain or loss to others, or intercepts a good which they had a reasonable hope of obtaining’. Mill's key example is market competition, in which the success of one can entail ‘the loss of others, from their wasted exertion and their disappointment’. Such ‘disappointed competitors’ can claim no moral or legal ‘immunity from this kind of suffering’ because it is ‘better for the general interest of mankind, that persons should pursue their objects undeterred by this sort of consequences’. Given this utilitarian rationale for allowing people to pursue legitimate objects, Mill maintains that interference should take place ‘only when means of success have been employed which it is contrary to the general interest to permit’, such as ‘fraud or treachery, and force’.⁷¹

As indicated above, in Non-Intervention Mill also attends to the distinction between legitimate and illegitimate objects when he distinguishes between defence and protection, on the one hand, and aggressive ‘aggrandizement’, on the other. Likewise, he distinguishes between legitimate and illegitimate ways of pursuing legitimate objects when he maintains that the British statesmen who will only contemplate interference for the sake of defence implicitly acknowledge that this is restricted to securing British ‘interests’ ‘against unfair arts, not against fair rivalry’.⁷² Thus, Mill implies, even if it were certain that Britain would suffer economic harm from canal-generated trade competition, this would not justify preventing its creation; fair rivalry is so conducive to the good of mankind that accepting the losses it generates is obligatory rather than supererogatory.⁷³

This point also parallels Mill's claim in Liberty that:

If poisons were never bought or used for any purpose except the commission of murder, it would be right to prohibit their manufacture and sale. They may, however, be wanted not only for innocent but for useful purposes, and restrictions cannot be imposed in the one case without operating in the other.⁷⁴

Analogously, if the only purpose that the Suez Canal could serve was aggressive warfare, those thus threatened by it would be justified in opposing its creation. However, since its principal purpose is not simply innocent but (extremely) useful, it would be illegitimate to oppose its creation to prevent its misuse.

Of course, one way in which the poison case differs from the canal case is that, although poisons might reasonably be supposed to pose a threat to all, Palmerston considered the canal a unique threat to British India. However, Mill follows both Roebuck and Gladstone in taking the uniqueness of this threat as an even greater reason, both morally and prudentially, for Britain not to oppose the canal. In parliament, Gladstone had warned against creating ‘hostility to the existence of British power in India’, by setting it ‘in opposition to the general interests of mankind’.⁷⁵ Mill goes somewhat further, declaring that a nation which ‘adopt[s] as a practical maxim, that what is good for the human race is bad for itself’ makes itself ‘the enemy of the human race’:

[s]o wicked a principle, avowed and acted on by a nation, would entitle the rest of the world to unite in a league against it, and never to make peace until they had, if not reduced it to insignificance, at least sufficiently broken its power to disable it from ever again placing its own self-interest before the general prosperity of mankind.⁷⁶

Given that preliminary building work had already begun on the canal at the time of writing,⁷⁷ Mill is warning Britain to recognize its error and back down. As indefensible as the diplomatic meddling had been, a point had been reached at which Britain could only meaningfully oppose the canal through escalation. However, to escalate beyond pressuring the Sultan to, say, threatening Egypt with military intervention or a blockade – as in the earlier crises involving Ali – would not simply render Britain an immoral aggressor state, it would imprudently entitle others to combine to defend themselves against abuses of British power.

The limits of military self-defence

Nevertheless, the preceding is compatible with Mill endorsing British opposition to the use of the canal for unfair forms of rivalry. In the second half of Non-Intervention, opening his case for the justifiability of at least some wars of protection, Mill suggests that ‘there assuredly are cases in which it is allowable to go to war, without having been ourselves attacked, or threatened with attack’.⁷⁸ This indicates that there is legitimate scope for defensive warfare in response to threats of unfair rivalry that are yet to be actioned. For example, if Napoleon III had seized the canal upon completion, and sent his navy through it to attack British India, Mill's position would not rule out Roebuck's aforementioned proposal of a pre-emptive naval war in the Red Sea.⁷⁹ However, it is less clear whether Mill construes the defence clause as leaving scope for just forms of what is now known as ‘preventive warfare’: designed to either eliminate the possibility or reduce the probability of an attack that remains non-imminent.⁸⁰ In this regard, Mill's view resembles that of his father, James Mill, who posited ‘state[s] of preparation’ for war that justify ‘the threatened nation in striking the first blow, in order not to give its enemy the advantage of completing his preparations, and making his attack just at the moment when it would be most destructive’, but was very ambiguous about cases in which the ‘evil’ is not ‘evidently impending’.⁸¹

In their speeches to parliament, although Roebuck insisted that the debate concerned a ‘wholly imaginary danger’,⁸² the most Palmerston would concede was that, if the canal were completed, a French attack ‘may not happen for a long period of time’.⁸³ The subtlety of the distinction would not have been lost on Roebuck because of his prior parliamentary dispute over the Crimean War with Richard Cobden MP: Britain's leading liberal theorist of foreign military intervention before Mill entered the debate.⁸⁴ Supporting Britain's participation, Roebuck had claimed that ‘it is our interest to go to war now – for [otherwise] we shall certainly have to go to war by and by […] under circumstances not nearly so advantageous as the present’; if Britain ‘were to abstain’, ‘Russia would take possession of Turkey’, ‘advance to Egypt’, and ‘cut us off from India and the East’.⁸⁵ Thus, while Roebuck's Crimean War speech allowed for just preventive self-defence, his Suez speech ruled out what contemporary strategists label a ‘precautionary’ subcategory thereof: ‘waged not on the basis of any noteworthy evidence of ill intent or dangerous capabilities but rather because those unwelcome phenomena might appear in the future’.⁸⁶ In contrast, when Cobden responded to the former speech, he echoed his semi-scholarly pamphlets opposing all forms of foreign military intervention other than the reactively (and possibly pre-emptively) defensive.⁸⁷ For example, chastising Roebuck's justification for the Crimean War ‘in the future tense’, he declared: ‘By the same rule, a man might bring one a bowl of poison, and say: – “You may as well take it now, because you will be sure to die some time”’.⁸⁸

Like Roebuck, Mill maintains that a mere ‘imaginable contingency’ in which the canal would be a ‘cause of inconvenience’ could not justify Britain depriving ‘the rest of mankind’ of the possibility of its ‘great advantage’.⁸⁹ This implies that Britain's meddling with the Sultan was precautionary, rather than merely preventive, and mirrors Roebuck's view that a war fought for the same purpose would be even further beyond the pale. Moreover, it gives a strong indication that Mill rules out precautionary warfare altogether unless it is directed against some kind of weapon or infrastructure whose only purpose is unambiguously unjust (like the poison whose sole use is ‘the commission of murder’).⁹⁰ For example, although Mill could not have foreseen 20^th-century gas chambers, this reasoning could be adduced in favour of an intervention to destroy one as a precaution against its only conceivable usage.

Of course, one might think that Mill's language is also specific enough to rule out preventive warfare altogether. In his discussion of the regulation of poisons in Liberty, Mill maintains that it ‘is one of the undisputed functions of government to take precautions against crime before it has been committed, as well as to detect and punish it afterwards’; ‘if a public authority, or even a private person, sees any one evidently preparing to commit a crime, they are not bound to look on inactive until the crime is committed, but may interfere to prevent it’.⁹¹ This much is insufficient to open the door to a criminal analogue of what is now meant by precautionary warfare, involving intercepting those who might commit a crime. After all, since Mill's would-be criminal is conceived as ‘evidently preparing to commit’ one, this implies sufficient evidence to attribute: (1) an intention to either commit the crime or acquire the wherewithal to make doing so a live option; and (2) actions taken as a deliberate means to that end. However, it is insufficient to rule out preventive criminal interceptions explicitly, as Mill does not state that the crime must be imminent.⁹² All Mill says is that the ‘preventive function of government […] is far more liable to be abused, to the prejudice of liberty, than the punitive function’.⁹³ In contrast, in the second half of Non-Intervention, Mill speaks explicitly of the ‘wickedness of commencing’ military action ‘for any interest of our own, except when necessary to avert from ourselves an obviously impending wrong’.⁹⁴ This would seem to rule out any preventive warfare altogether, as it is difficult to construe an impending wrong as anything other than imminent.

Nevertheless, Mill's final position is far more subtle than that. This can be seen by juxtaposing his preceding point about pre-emptive defensive military action with the way he qualifies his claim that British statesmen should also be open to foreign military interventions for the sake of altruistic protection upon request: it is ‘seldom […] either judicious or right, in a country which has a free government’, to use military intervention or aid ‘to assist […] the endeavours of another to extort the same blessing from its native rulers’.⁹⁵ This reduces the scope for protective foreign military intervention to a narrow range of cases: assistance to one foreign people defending itself against the aggression of another; multilateral enforcement of the cessation of a ‘protracted civil war’; and prevention of ‘severities repugnant to humanity, and injurious to the permanent welfare of the country’.⁹⁶ Since the last case is supposed to differ from one in which a group requests protective support to help it establish ‘free government’, Mill cannot include the lack thereof among the said ‘severities’.⁹⁷ Consequently, Walzer⁹⁸ was mistaken to suggest that Mill does not allow for what we now call humanitarian intervention to prevent the worst forms of human rights abuses.⁹⁹

Mill does not state if, or when, such morally permissible acts of protection upon request become morally obligatory. However, his judgements indicate that this is most likely when the risk involved for the would-be protector is relatively low compared to the danger from which the would-be protectee seeks to be shielded. For example, although Mill only calls the ‘interference of the European Powers [France, Russia, and Britain] between Greece and Turkey’ in the Greek War of Independence (1821–29) ‘warranted’ rather than obligatory,¹⁰⁰ one reason it was relatively uncontroversial was that their alliance could overcome Ottoman Turkey with relative ease. Likewise, Mill's readers would have known that a key reason the governments of those states overcame their initial reluctance to involve themselves was the mass public outrage at the Caliphate's asymmetric slaughter of its rebellious dhimmis.¹⁰¹

At the opposite end of the spectrum, Mill says that, although it would have been ‘honourable and virtuous’ (i.e. noble) for ‘England’ to have engaged in a protective counter-intervention when Russia sent its forces to help the Austrian monarchy crush the liberal nationalist Hungarian revolt of 1848–49, it ‘might not have been consistent with the regard which every nation is bound to pay to its own safety’ (i.e. prudence) to have done so ‘single-handed’. Moreover, although Mill goes on to say that ‘England and France together could have’ led a successful counter-intervention, or used the threat thereof to deter Russian intervention in the first place, he still seems to consider this (morally) supererogatory from a purely protective perspective. For example, when he declares that it would be ‘heroic’ for a nation, ‘powerful enough to make its voice effectual’, to be the first to have the ‘spirit and courage to say that not a gun shall be fired in Europe by the soldiers of one Power against the revolted subjects of another’, he does not claim that anything falling short of that is immoral or blameworthy,¹⁰² let alone an outright injustice.¹⁰³

As a result, Mill's position opens the door to a range of cases in which counter-intervention is supererogatory from a purely protective perspective but potentially prudent from the perspective of preventive self-defence. For example, Mill says that the collective failure of Britain and France to counter-intervene in the Hungarian case, because they considered no vital interests to be under immediate threat, meant that ‘they had to fight Russia five years afterwards [in the Crimean War], under more difficult circumstances, and without Hungary for an ally’.¹⁰⁴ During the earlier crises involving Ali, Mill seems to have denied it was necessary to protect Turkey from Russia to ensure that the former could serve as a buffer defending British India, so it is unclear whether he thought that the Crimean War was really necessary for defensive purposes.¹⁰⁵ However, the underlying principle is evident: once the aggression of a despotic power against a third party renders it morally permissible for a liberal power to engage in protective military action, the latter may proceed even though its primary motivation is to prevent the despotic power from becoming a direct threat to its own security in the future.¹⁰⁶

The reason for this seems to be that, when it comes to wars fought for defensive purposes, Mill treats the aggression of a despotic power against a third party as the functional analogue of the evidence of criminal intent and preparation that licenses preventive policing.¹⁰⁷ Moreover, he does so because he believes that if one European despotism aggresses against the liberal forces in a neighbouring European state, as Russia had done against the Hungarian rebels in 1849, this is evidence of a threat to more distant third-party liberal states such as Britain. After all, he reasons, since Britain's ‘freedom […] is a standing reproach to despotism everywhere, and an encouragement to throw it off’, the ‘contingency’ in which it finds itself ‘menaced with attack by a coalition of Continental despots’ is ‘by no means unlikely’.¹⁰⁸ In other words, Mill takes the mere existence of Britain's political system to pose such a great non-military threat to the legitimacy and survival of the European despotisms that they would crush it militarily if the balance of power permitted.¹⁰⁹ For Mill, that gave Britain a defensive interest in the success of liberal nationalist movements abroad; each new liberal state was not simply one less potential member of the said despotic coalition but also one more potential member of an ‘alliance of free peoples, so strong as to defy the efforts of any number of confederated despots to bring it down’. Thus, contemplating the possibility of Britain declaring that it will counter-intervene whenever a despotic state intervenes to crush a liberal uprising in a neighbouring territory, Mill says that ‘the time may not be distant when’, ‘if she does not take this heroic part because of its heroism [i.e., noble altruistic protection], [she] will be compelled to take it from consideration for her own safety [prudent self-defence]’.¹¹⁰

Liberal states of exception and the primacy of self-defence

It may seem unremarkable that Mill deems it morally permissible for a liberal state to engage in wars with protective effects even if they are only motivated by defensive considerations. After all, given Mill's place in the consequentialist utilitarian tradition, one might expect him to consider it more important that a vulnerable agent is protected than that the protector is nobly altruistic or heroic in the process. However, as will become clear, this would be to ignore the resultant tensions in Mill's position, born of how defensive and protective considerations can pull in different directions.

When Mill says that protective considerations (i.e. the protection clause) cannot be used to justify military intervention to help liberal rebels overthrow a ‘native tyranny’ he suggests it is morally inexpedient because it is unlikely to be good for the country concerned:

The only test possessing any real value, of a people's having become fit for popular institutions, is that they, or a sufficient portion of them to prevail in the contest, are willing to brave labour and danger for their liberation […] If a people – especially one whose freedom has not yet become prescriptive – does not value it sufficiently to fight for it, and maintain it against any force which can be mustered within the country, even by those who have the command of the public revenue, it is only a question in how few years or months that people will be enslaved.¹¹¹

For the purposes of this paper, it is unnecessary to dwell on the details of Mill's argument for the adequacy of this test.¹¹² It suffices to say that Mill opposes such intervention because he deems it unlikely to produce an enduring liberal government, and thus likely to result in both lives lost in vain, and greater setbacks to the cause of liberalism than if it had not been imposed prematurely. However, Mill also claims that there are ‘exceptions’ to his moral prohibition on liberal states seeking to support liberal regime change from without. Moreover, he insists that this is not because of any ‘failure’ of the ‘reasons’ (i.e. his test) that normally counsel against it, but rather because there are ‘considerations’ that are ‘paramount to them’ coming ‘under a different principle’ (i.e. the defence clause).¹¹³

Mill describes one exceptional scenario, raising difficult questions about jus post-bellum, as follows:

when a nation, in her own defence, has gone to war with a despot, and has had the rare good fortune not only to succeed in her resistance, but to hold the conditions of peace in her own hands, she is entitled to say that she will make no treaty, unless with some other ruler than the one whose existence as such may be a perpetual menace to her safety and freedom.¹¹⁴

The real-world example Mill seems to have in mind is the allied imposition of a constitutional monarchy in France, through the Bourbon Restoration, following the Napoleonic Wars. However, since Mill is also writing prescriptively for posterity, the example suggests that Britain might legitimately help to impose a genuinely liberal government on a vanquished despotic aggressor state in the future. In this regard, Mill implies that the defence clause can make it permissible to assist friendly liberal forces in an enemy state even if their victory would risk the country being subjected to a premature postbellum political experiment. It was noted above that Mill thinks it may be supererogatory for a liberal state to accede to a prudent request for protection, by a foreign people subjected to aggression, when doing so would be defensively imprudent. Here the converse implication is that it may be supererogatory for a liberal state to refuse an imprudent request for protection, by a would-be friendly government-in-waiting, when proceeding would be defensively prudent.

Mill's other exceptional scenario gives an Anglo-liberal spin to Vattel's claim¹¹⁵ that French support for German Protestant rebels in the Holy Roman Empire in the 1540s was a just means of preventing Charles V of Spain from becoming the hegemon of Europe. A liberal power ‘menaced with attack by a coalition of Continental despots’, Mill declares, ‘ought to consider the popular party in every nation of the Continent as its natural ally, the Liberals should be to it, what the Protestants of Europe were to the Government of Queen Elizabeth [r. 1558–1603]’.¹¹⁶ The daughter of Henry VIII (r. 1509–47) – excommunicated and threatened with a crusade in the 1530s¹¹⁷ – Elizabeth's reign commenced shortly before France and Spain signed articles in the Treaty of Cateau-Cambrésis (1559)¹¹⁸ declaring ‘a joint commitment to extirpate Protestantism’.¹¹⁹ Two historiographies of the Elizabethan period Mill acknowledges reading,¹²⁰ authored by David Hume¹²¹ and William Robertson,¹²² offer highly sympathetic accounts of her response from late 1559 to 1560. Both emphasize the clarity of the threat that France posed to Elizabeth through its open rejection of her legitimacy, and its pre-existing military presence in Scotland in support of its French Catholic Regent, Mary of Guise. Moreover, both conclude this gave her little choice but to agree to a counter-intervention on behalf of Protestant Scottish rebels, who had requested the English assist them in expelling the French, lest their defeat pave the way for a French invasion of England.

For his part, Robertson articulates the justificatory ‘principle’ offered by William Cecil, Elizabeth's chief advisor, in terms of ‘every society’ having ‘a right to defend itself; not only from present dangers, but from such as may probably ensue […] In political conduct, it is childish to wait till the designs of an enemy be ripe for execution’.¹²³ Likewise, Hume recounts that, ‘having sent over […] incontestable proofs’ of France's ‘hostile intentions’, Nicholas Throckmorton, ‘the English ambassador at Paris’, claimed that ‘nor could any doubt be maintained with regard to the justice of a measure [counter-intervention], founded on such evident necessity, and directed only to the ends of self-preservation’.¹²⁴

However, Mill's reference to Elizabeth does far more than justify this particular counter-intervention against France, and that which she undertook in the Netherlands in the spring of 1585 after her ‘council agreed that war against Spain was inevitable and it was more sensible to fight at the present time as allies of the [Dutch] States than to face a future Spanish invasion alone’.¹²⁵ One lesson that can be derived from Robertson's account of the counter-intervention in Scotland is the utility of unilateral intervention for self-defence. After all, he implies, since the troubles brewing in France, portending the outbreak of the French Wars of Religion (1562–98), compelled it to withdraw troops to the homeland, the revolt of the persecuted French Protestants had effectively rendered them England's first line of defence.¹²⁶ This translated into a defensive rationale for sending English troops to support Louis de Bourbon, Prince of Condé, as he led a Huguenot rebellion against the Catholic Guise faction of the nobility and the Catholic Regent of France, Catherine de' Medici (r. 1560–63). Moreover, this rationale was reinforced by intelligence suggesting that a victory for the Guise would grant France a free hand to ally with Spain (Mill's ‘coalition of despots’¹²⁷) with the war aim of invading England – an Elizabethan fear that mirrored Mill's contemporaneous concern that if France and Russia dispensed with Austria, their next move would be to attack Britain. For example, in 1562, arguing that the formation of a Franco–Spanish alliance must be prevented, Cecil warned that if the ‘papists shall have the upper hand’, ‘then will it be to late to seke to withstand it for then the matter shall be lyke a great rock of stone that is fallyng downe from the topp of a mountayne which when it is comyng no force can stey’.¹²⁸ Likewise, drawing the obvious conclusion, Throckmorton said of unilateral military intervention on the part of the Huguenots, ‘[h]er majestie may make to hirselfe suche suertie [security]’, and ‘perhaps proffit, as musiciens make melody of discorde’.¹²⁹

Consequently, Mill's Elizabethan analogy indicates that it becomes much easier to justify military intervention for the sake of defence when a liberal state is in evident and serious danger of being invaded by stronger despotic foes, and waiting to act is likely to make the danger worse. In that scenario, Mill implies, the liberal state may grant protective military support to liberal resistance movements within the said despotic states to tie the latter down and prevent them from aggressing against it directly. Moreover, it may do so before the invasion is imminent.

Doyle's objections

Unfortunately for Elizabeth, the subsequent military intervention of 1562–63 ended in a debacle.¹³⁰ ‘[B]esides’ furthering, what Hume refers to as, ‘the general and essential interest of supporting the protestants’, Elizabeth also saw the intervention as an opportunity to seize French territory, thereby making Condé appear ‘treasonable’ for having ‘granted’ her ‘an entrance into the heart of the kingdom’.¹³¹ Consequently, once he no longer needed Elizabeth's assistance, Condé violated their agreement by suing for peace with Medici independently, and then joining forces with the latter temporarily to force Elizabeth's army into a humiliating withdrawal.¹³²

Attending to this denouement, Doyle objects that Mill's ‘case does not seem to vindicate the policy’; the lesson Elizabeth learned was contrary to Mill's own as she became far more cautious in the future.¹³³ However, Mill could approve of this particular intervention insofar as it served the ‘essential [defensive] interest of supporting the protestants’, without approving of the territorial aggrandizement which helped to turn them against her.¹³⁴ After all, Hume's account implies that Elizabeth only became ‘less intimate’ with Condé after the protective intervention had served its defensive purpose by helping to make the threat to the Protestants ‘not so imminent’.¹³⁵ Moreover, the lesson Elizabeth learned was not to forgo unilateral military intervention altogether. For example, in 1589, she engaged in another unilateral intervention in France on behalf of the new, but excommunicated and beleaguered, Protestant king, Henry IV (r. 1589–1610). According to Wallace MacCaffrey, the English ‘augmentation to the royal forces’ was ‘crucial to Henry's success’ on ‘several occasions’. Refraining from any opportunistic aggrandizement, the English troops were also cautiously withdrawn as soon as Henry's survival was assured,¹³⁶ thereby concluding what Hume describes as a ‘campaign’ that ‘revived in France the ancient fame of English valour’.¹³⁷ Although the English troops had to return to France shortly thereafter, to counter-intervene against Spanish troops,¹³⁸ one can see why Mill might have thought of this case as vindicating the policy.

Doyle's next concern is that Mill's Elizabethan analogy ‘resonates in twentieth-century Cold War logic and neatly matches the rhetoric of the Reagan Doctrine, which pledged, “We must not break faith with those who are risking their lives…on every continent from Afghanistan to Nicaragua…to defy Soviet aggression and secure rights which have been ours since birth. Support for freedom fighters is self-defense”’.

Judging that position unjustifiable, Doyle infers that ‘we should go beyond Mill’ to embrace ‘more proximate conceptions of “legitimate self-defense”’; the ‘rampant interventionism invoked in Cold War diplomacy’ is ‘much too costly, both in treasure and lives, to qualify as national security’.¹³⁹ On this view, Mill's error is to adopt an over-capacious conception of self-defence that smuggles in elements of aggression. However, since the holistic interpretation of Non-Intervention adopted here reveals that this is the error Mill attributes to Palmerston, he may have been more careful to avoid it than Doyle acknowledges.

One might think that the interpretive component of Doyle's objection can be supported by an earlier article that Mill wrote justifying the revolution that yielded the Second French Republic (1848–52). While discussing Alphonse de Lamartine, one of the more moderate revolutionaries, Mill defends him for asserting ‘a right, though without admitting an obligation, to afford military aid to nations attempting to free themselves from a foreign yoke’.¹⁴⁰ Then, having insisted that de Lamartine's critics are mistaken to accuse him of asserting a right to assist rebellions ‘against native rulers’, Mill makes a slightly puzzling move by appearing to assert it himself.¹⁴¹ Pre-figuring his discussion of the ‘Reformation’ in Non-Intervention, Mill compares the period to his own and asks:

Did any one then pay the least regard to the pretended principle of non-interference? Was not sympathy of religion held to be a perfectly sufficient warrant for assisting anybody? Did not Protestants aid Protestants, wherever they were in danger from their own governments? Did not Catholics support all other Catholics in suppressing heresy? What religious sympathies were then, political ones are now; and every liberal government or people has a right to assist struggling liberalism, by mediation, by money, or by arms, wherever it can prudently do so; as every despotic government, when its aid is needed or asked for, never scruples to aid despotic governments.¹⁴²

It is unclear whether the final clause is supposed to imply that the right to military intervention exists only if the despotic governments do not scruple to intervene.¹⁴³ Nevertheless, even if we were to suppose that the position Mill defends here lacks that qualification, what would make it so permissive is not the general conflation of protection with defence suggested by Doyle. It is rather that Mill would be allowing for non-defensive, unilateral military intervention to protect liberal movements from despotic governments as such as opposed to ‘severities repugnant to humanity’.¹⁴⁴

In contrast, in Non-Intervention Mill implies that if the balance of power were so favourable to a liberal state that self-regarding prudence was no restraint, it would constitute impermissible aggression or morally inexpedient recklessness for it to use military force against a despotic state that wasn't guilty of either (imminent) external aggression or internal atrocity respectively.¹⁴⁵ Of course, Non-Intervention also indicates that the European despotisms would struggle to survive without recourse to aggression or atrocity, not least because Mill takes liberal states to be entitled, if not obligated, to support foreign liberal dissidents through ‘the moral support of […] opinion’.¹⁴⁶ However, that is consistent with the impermissibility of either trying to win that battle of opinion through (the threat of) military force, or resorting thereto when a despotic regime seeks to secure itself through forms of repression falling short of atrocity.¹⁴⁷

One possible response on Doyle's behalf is that, when he likens the salient part of Mill's position in Non-Intervention to the Reagan Doctrine, his concern is with the implications of the former for a bipolar order, in which a liberal coalition faces off against a despotic one, and the two poles are sufficiently powerful to deter either side from attacking the other directly. Thus construed, Doyle worries that Mill's position would still permit the liberal states to promote their cause in any remaining non-aligned states, through unilateral military intervention, in the name of self-defence. However, that a liberal analogue of Elizabethan England, facing a grave asymmetric threat of conquest, would be permitted to prevent this through unilateral military intervention, does not entail that it would be permitted to take the same measures when powerful enough to rely on conventional deterrence alone. In this regard, Doyle's interpretive claim rests on an invalid extrapolation.

The preceding also points to two further reasons why Doyle's Reagan Doctrine examples are unsuitable to illustrate the contemporary implications of Mill's position. The first is that, regardless of one's moral evaluation of the Reagan Doctrine, the Nicaraguan Contras (with their death squads)¹⁴⁸ and the Afghan Mujahideen (with their jihadist terror tactics),¹⁴⁹ were very far removed from what Mill means by ‘struggling liberalism’.¹⁵⁰ In response, Doyle might note that, in an even earlier article, Mill declares that:

Self-defence justifies much: Revolutionary France, standing at bay against all the despots in Europe, had the amplest justification for invoking, in the name of universal liberty, the aid of every disturbed spirit in Europe, who might respond to the call.¹⁵¹

After all, might some of these disturbed spirits be illiberal, unscrupulous characters? Perhaps, but even if that were the case, it would be a scenario in which the threat of invasion is so severe that the plea for protection is addressed to them. Furthermore, turning to the second point, insofar as there were threats of invasion and charges of (ideological) heresy in the Nicaraguan case, they were made by the United States against the Sandinista government.¹⁵² In that regard, the United States' role bore little resemblance to Mill's embattled liberal analogue of Elizabethan England.

Conclusion

By distinguishing between Mill's defence and protection clauses, and the key role that the former plays in both halves of Non-Intervention, it becomes possible to discern the philosophical thread that makes the text a coherent whole rather than a disjointed medley of parochial political commentary and timeless moral theory. In the first half, Mill highlights the novelty and merit of a nation committed to avoiding aggression by following a foreign policy constrained by the defence clause, while emphasizing the need to communicate that commitment more effectively to foreign powers. However, he also uses the discussion of Palmerston's Suez policy to illustrate how the legitimate desire for security can morph into an illegitimate desire for dominance, one natural tendency of which is to seek to sustain itself through precautionary aggression.¹⁵³ In the second half of Non-Intervention, Mill moves on to illustrate the ethical deficiencies of a foreign policy in which force and coercion are permitted via the defence clause alone. Provided it is constrained by an imperative of moral expediency, prohibiting assistance when it would do more harm than good, protective intervention can be morally permissible and perhaps even obligatory. However, judging many morally permissible acts of foreign military protection to be supererogatory, and aware that many people and governments are not noble enough to employ force altruistically beyond the call of duty, Mill highlights how they can also be recommended to a liberal state as a form of defensive prudence.¹⁵⁴ In that regard, although the first half of Non-Intervention warns against conceptions of self-defence that are too broad, the second half warns against those that are too narrow, with the case studies illustrating how defence can go beyond deterring, pre-empting, or responding to direct aggression, by incorporating protective activities that prevent it.

Perhaps the most controversial implication of that latter discussion pertains to cases in which a liberal state is facing a non-imminent but existential threat of invasion by a more powerful despotic foe. Here Mill appeals to the defence clause to argue that it can be both morally permissible and prudent to seek to prevent that aggression by providing protective support upon request to liberal resistance groups inside the despotic state. One reason this may surprise Mill's readers is that he usually opposes such assistance as morally inexpedient when conducted on protective grounds, due to his belief that liberal governments established that way are unlikely to endure. A second reason it may be surprising stems from the fact that such unilateralism may only be effective by sparking or exacerbating a civil war, just as the Elizabethan interventions helped to prolong the French Wars of Religion by precluding the dominant Guise faction from sealing victory. Since Mill also offers the multilateral enforcement of the cessation of a civil war as an example of just protective intervention, this is a case in which his ethical reasoning about defence is not simply different from his ethical reasoning about protection but at odds with its practical prescriptions.

However, although this introduces tension into Mill's position, he seems to consider this necessary to account for the genuine moral complexity of ‘the most delicate [subjects] in political ethics; […] concerned with that nice question, the line which separates the highest right from the commencement of wrong; where one person regards as heroic virtue, what another looks upon as breach of faith, and criminal aggression’.¹⁵⁵ Moreover, Mill has three key ways of ensuring that this tension does not generate an outright contradiction: (1) acknowledging that his international theory gives ethical primacy to defence over protection¹⁵⁶; (2) highlighting that protection may also favour the prolongation of a civil war if the alternative is for it to end in a massacre or the perpetuation of great injustice¹⁵⁷; and (3) insisting that assistance must be upon request, as opposed to imposed paternalistically for the recipient's own good.¹⁵⁸ Finally, observing the grand strategic terrain from an even loftier height, Mill's personal correspondence hints at a further utilitarian consideration: that the interest the members of a despotic state may have in avoiding a premature liberal revolt, or even an outright civil war, is secondary to mankind's interest in their country not invading the likes of his own. After all, he observes, if a beleaguered liberal Britain were to fall to a continental despot, the light of liberty could be extinguished in Europe.¹⁵⁹