This chapter dissects the challenges posed by weapons of mass destruction. It starts by exploring the weapon that changed the fundamentals of security and warfare – the atomic bomb with a brief look at how nuclear weapons work. Then it examines three cases focused on nuclear weapons: nuclear weapons in the Cold War, nuclear-weapon states in the twenty-first century, and non-state actors and the nuclear dilemma. The chapter rounds out with a look at the role chemical and biological weapons play in the contemporary world, offering some concluding thoughts on weapons of mass destruction and contemporary international security.

Wise governance for nuclear weaponry and synthetic biology requires humankind to move more swiftly than today in certain technological domains, while actively slowing down the pace in other areas. For example, advancing technologies for aerial and space-based surveillance, coupled with AI for interpreting the resulting high-resolution images, could allow nations to track in real time the location of other nations’ nuclear missile submarines. Such a development would remove one of the fundamental stabilizing factors in today’s military affairs: the guarantee of a second-strike capability, which lies at the heart of nuclear deterrence. These kinds of technological breakthroughs urgently need to be restrained via diplomatic agreements akin to the superpowers’ arms control treaties during the Cold War. Similarly, the existing “Wild West” in synthetic biology and AI requires swift governmental action to create effective regulatory frameworks for these fields, both within nations and among nations.

President John F. Kennedy was elected on a program of change. Despite his electoral rhetoric, in office, he was cautious and fiscally conservative. He felt especially vulnerable on economic issues with a nagging balance of payments deficit that threatened the role of the dollar in the international monetary system. He chose Republicans for the two agencies that had the greatest bearing on the balance of payments: C. Douglas Dillon as Secretary of the Treasury and McNamara as Secretary of Defense. At the same time, Kennedy’s interest in the developing world was different from his predecessors’ and led him to experiment with new ways of projecting US power internationally, including through building up local capabilities to fight “wars of national liberation.” His national security bureaucracy changed accordingly with the creation of a Special Group on Counterinsurgency, the US Agency for International Development (USAID), the Peace Corps and with a renewed focus on the US Army’s Special Forces.