Grey gave a great push to convince his colleagues to consult the French government about activating the House-Grey Memorandum, only to be outmanoeuvred. With this diplomatic alternative set aside, the military successfully pressured the government to assent to a major summer offensive on the Somme. The military also sought to replace the strategy agreed a few months earlier with an economic fantasy: the military was now looking to win the war with an offensive in 1917 instead of in 1916, but refused to accept that Britain would face serious financial problems in continuing the Allies' massive US supplies through a 1917 campaign. Despite fierce resistance within the Cabinet, the House of Commons forced the acceptance of the military's position. The British government suffered a financial scare when McKenna warned that their assets deployable in the United States faced exhaustion by autumn. McKenna was wrong about the timing: Britain had more assets than he thought, enough to last them into early 1917. But the scare resulted in a serious reconsideration of the House-Grey Memorandum when House and Wilson pushed for an autumn implementation of the agreement. The memorandum's proponents were unintentionally undermined by Wilson’s speech to the US League to Enforce Peace.

In the aftermath of German-American diplomatic crisis over submarines, House conceived a new, more ambitious strategy of trying to use US power to end the war and prevent an Allied defeat. Although House initially struggled to find a receptive audience amongst the British leadership, anxiety within the British government was on the rise. Efforts to reconcile Britain's economic and military strategies settled on a plan to win the war with a great 1916 offensive – a strategy that provoked serious disquiet amongst a number of key British leaders. By February 1916, a number of British leaders, including Foreign Secretary Sir Edward Grey, encouraged House towards a still more ambitious conception of American mediation: not only would the United States play a key role in setting up the negotiations, but it would also chair them. House and Grey agreed the 'House-Grey Memorandum', in which House promised that the United States would guarantee a set of limited Allied war aims at a peace conference. All the while, British intelligence was decrypting House's telegrams and attempting to undermine his negotiations.

Chapter 4 chronicles how Walter Hines Page, a diplomatic novice when President Woodrow Wilson tapped him to head Embassy London, proved one of the pivotal actors in World War I. While Wilson - and most of his cabinet - strove to maintain American neutrality in this conflict, Page, virtually from the moment hostilities erupted, strained every nerve and sinew to bring Washington into the war on the side of the Allies, especially Britain. The White House and State Department were unresponsive to Page's entreaties for many months - indeed, he was frequently threatened with cashiering - but his relentless cannonade of cables, letters, and other forms of trans-Atlantic arm-twisting bore fruit when Wilson accepted the logic of the ambassador's main argument: that German domination of the Continent would pose an unacceptable menace to the Western Hemisphere. Wilson's famous proclamation to Congress that "the world must be made safe for democracy" was a virtual paraphrase of Page's correspondence. Many interwar American historians, among them Harry Elmer Barnes and C. Harley Grattan, considered U.S. entry into the so-called "Great War" a calamity and blamed Page for nudging America off the tightrope of neautrality. I argue that this charge - oft-belittled in the post-World War II period - was in fact largely correct, but that Page's insubordination was heroic rather than nefarious.