Introduction
Most states with nuclear weapons maintain policies that would permit their first use in a conflict. Pledges to only use these weapons in retaliation for a nuclear attack—or a no-first-use (NFU) policy—are rare. Where these pledges have been made by nuclear states, their adversaries generally consider them not credible.



Strategic planners for nuclear weapons powers see the credible threat of the first use of nuclear weapons as a powerful deterrent against a range of significant nonnuclear threats, including major conventional, chemical, and biological attacks, as well as cyberattacks. Even states with significant conventional military forces, such as the United States, consider it necessary to retain nuclear first use as an option. The 2018 Nuclear Posture Review, under the administration of President Donald J. Trump, retains the option of nuclear first use.



What is the debate in the United States on NFU?
Though the 2010 Nuclear Posture Review did not include an NFU pledge, the Obama administration considered the idea during its second term. It ultimately left U.S. nuclear declaratory policy unchanged from its 2010 iteration, which stated that the United States reserved the right to use nuclear weapons to deter nonnuclear attacks while strengthening conventional capabilities to gradually reduce the role of nuclear weapons to that of solely deterring nuclear attacks. Nevertheless, the Obama administration’s final year in office saw animated debate among proponents and opponents of an NFU declaration.

Arguments in favor of a U.S. NFU pledge. Proponents of a U.S. NFU declaration have argued that not only does the United States already maintain a de facto NFU policy but that U.S. superiority in conventional weapons is sufficient to deter significant nuclear, biological, chemical, and conventional threats. Additionally, as Kingston Reif of the Arms Control Association has argued, “a clear U.S. no-first-use policy would reduce the risk of Russian or Chinese nuclear miscalculation during a crisis by alleviating concerns about a devastating U.S. nuclear first-strike.” In nuclear strategy, a first strike refers to a nuclear attack that seeks to disarm a nuclear-armed enemy before it can employ its weapons.

Other proponents pointed to an NFU policy declaration being a necessary step on the road to global nuclear disarmament, an aspirational goal of the Obama administration and a requirement for all recognized nuclear weapon states under Article VI of the NPT. Proponents also argue that U.S. resistance to an NFU declaration has harmed U.S. nonproliferation efforts.