Nuclear weapons are different from every other type of weapons technology. Their awesome destructive potential and the unparalleled consequences of their use oblige us to think critically about the ethics of nuclear possession, planning, and use. Joe Nye has given the ethics of nuclear weapons deep consideration. He posits that we have a basic moral obligation to future generations to preserve roughly equal access to important values, including equal chances of survival, and proposes criteria for achieving conditional or “just deterrence” to minimize the risk of nuclear use and help preserve these values. While Nye's conditions are laudable, they are not achievable. They rely on flawed assumptions about the nature of nuclear weapons and the inherent risks of the nuclear deterrence system. Since the Cold War ended, the strategy and practice of nuclear deterrence has grown riskier, more urgent, more dangerous, and less stable. It is time to rethink how we manage nuclear risks. A new nuclear security system must be built on the design principle that the consequences of system failure cannot threaten to end or fundamentally disrupt civilization. We owe the future a new nuclear security strategy that can prevent an existential global nuclear event.

Scott Sagan asked me to revisit Nuclear Ethics, a book I published in 1986, in light of current developments in world affairs. In doing so, I found that much had changed but the basic usability paradox of nuclear deterrence remains the same. As do the ethical dilemmas. To deter, there must be some prospect of use, but easy usability could produce highly immoral consequences. Some risk is unavoidable and the moral task is how best to lower it. Nuclear weapons pose moral problems but nuclear use is the greater evil. Abolition may be a worthy long-term goal, but it is unlikely in the short-term relations among the nine states now possessing nuclear weapons. Drawing on just war theory, I examine the three dimensions of intentions, means, and consequences to outline a ten-point agenda for just deterrence that seeks to lower risks of nuclear war. The world has changed since the book was published but the basic moral dilemmas remain the same.

Why has interstate war declined and why do states refrain from territorial conquests in the post-Second World War order? The 1928 Peace Pact cannot account for these remarkable developments. This article argues that outlawing war is not enough to promote international peace. International Relations debates on the influence of weapons of mass destruction, democratic regime types and political cultures on interstate behaviour provide further important insights into the delegitimation of certain types of war. Since the 1990s, a changing character of war and warfare has emerged that is especially promoted by democratic states. How democratic states have justified their military use of force and how they have conducted their military interventions has a strong and ambivalent impact on the liberal world order.

This article describes the genesis of the humanitarian initiative and the political context in which it has developed in the course of the joint cross-regional statements and the three international conferences on this issue in Norway, Mexico and Austria. It examines the key substantive conclusions that have emerged as a result of this debate and assesses their relevance for the global nuclear disarmament and non-proliferation regime. It concludes that these facts and findings warrant an urgent reassessment of the so-called security value of nuclear weapons and a nuclear deterrence-based notion of stability and security.

Once again, the politically volatile Middle East and accompanying rhetoric has escalated the risk of a major nuclear exchange. Diplomatic efforts have failed to make the medical consequences of such an exchange a leading element in negotiations. The medical and academic communities share this denial. Without exaggeration, the harsh reality of the enormous consequences of an imminently conceivable nuclear war between Iran and Israel will encompass an unprecedented millions of dead and an unavoidable decline in public health and environmental devastation that would impact major populations in the Middle East for decades to come. Nuclear deterrence and the uncomfortable but real medical and public health consequences must become an integral part of a broader global health diplomacy that emphasizes health security along with poverty reduction and good governance.