Recent press reports indicate that the Obama Administration might adopt a declaratory policy stating that the United States will not be the first to use nuclear weapons in conflict. These reports have reignited debate about the benefits and risks of this policy, known as a "no first use" pledge. U.S. officials have repeatedly stated that the United States could, under certain circumstances, use nuclear weapons against a state, even if the latter has not already done so. The absence of a "no first use" pledge dates back to the Cold War when the United States sought to deter a Soviet attack on the United States and its allies in Europe. The United States has modified its policy to reduce the apparent role of nuclear weapons, but has still not declared that it would not use them first.
The United States has pledged to refrain from using nuclear weapons against most non-nuclear weapon states, but has neither ruled out their first use in all cases nor specified the circumstances under which it would use them. This approach, known as "calculated ambiguity," addressed U.S. concerns during the Cold War, when the United States and NATO faced numerically superior Soviet and Warsaw Pact conventional forces in Europe. At the time, the United States not only developed plans to use nuclear weapons on the battlefield to disrupt or defeat attacking tanks and troops, but it also hoped that the risk of a nuclear response would deter the Soviet Union from initiating a conventional attack. This is not because the United States believed it could defeat the Soviet Union in a nuclear war, but because it hoped the Soviet Union would know that the use of these weapons would likely escalate to all-out nuclear war, with both sides suffering massive destruction.
U.S. officials have occasionally considered adopting a "no first use" pledge, but the policy has remained largely unchanged since the end of the Cold War. In the 2010 Nuclear Posture Review Report, the Obama Administration stated, "The fundamental role of U.S. nuclear weapons ... is to deter nuclear attack on the United States, our allies, and partners." According to the report, the United States "would only consider the use of nuclear weapons in extreme circumstances" and would not threaten or use nuclear weapons, under any circumstances, "against non-nuclear weapons states that are party to the Nuclear Nonproliferation Treaty and in compliance with their nuclear non-proliferation obligations." For states not covered by this assurance, the Administration was not prepared to state that the "sole purpose" of U.S. nuclear weapons is to deter nuclear attack because it could envision "a narrow range of contingencies" where nuclear weapons might play a role in deterring conventional, chemical, or biological attacks.
Although the United States does not rule out the first use of nuclear weapons, the absence of a "no first use" pledge is less about the perceived need to employ these weapons first in a conflict than it is about the view that the threat of nuclear escalation continues to serve as a deterrent to large-scale conventional war or the use of chemical and biological weapons. Supporters of the current policy argue that removing the threat of nuclear escalation could embolden countries like North Korea, China, or Russia, who might believe that they could overwhelm U.S. allies in their regions and take advantage of local or regional conventional advantages before the United States or its allies could respond. In such a scenario, some argue, the "no first use" pledge would not only undermine deterrence, but could also increase the risk that a conventional war could escalate and involve nuclear weapons use. Moreover, because the United States has pledged to use all means necessary, including nuclear weapons, to defend allies in Europe and Asia, this change in U.S. declaratory policy could undermine allies' confidence in the U.S. commitment to their defense and possibly spur them to acquire their own nuclear weapons. As a result, in this view, a "no first use" policy could undermine U.S. nuclear nonproliferation goals.
Some analysts outside government dispute these conclusions. Some assert a lack of evidence that the threat of nuclear escalation can deter conventional war, while others note that U.S. nuclear first-use might spark a nuclear response and an all-out nuclear exchange. Moreover, some contend that a "no first use" policy would not undermine the U.S. commitment to its allies because those states have faith in U.S. conventional forces for their defense, as well as knowledge of the U.S. willingness to retaliate with nuclear weapons in response to nuclear attacks. As a result, they conclude that the possible first use of nuclear weapons is not only unnecessary, but also might turn conventional war into a nuclear catastrophe. Moreover, they argue that "no first use" would support U.S. nonproliferation goals by demonstrating that the United States accepted a limited role for its nuclear force.
Press reports indicate that both military and civilian officials in the Obama Administration oppose a "no first use" pledge. Air Force officials have argued that current ambiguity provides the President with options in a crisis. Admiral Haney, the Commander in Chief of Strategic Command, has noted that the shift could undermine deterrence and stability in an uncertain security environment. Secretary of State Kerry and Secretary of Defense Carter have raised concerns that a "no first use" policy could undermine the confidence and security of U.S. allies. Secretary of Energy Moniz also expressed opposition. Reports indicate that several allies have also weighed in against the change in policy. Congress remains divided, with some, like Senator Dianne Feinstein, arguing that the only moral use for U.S. nuclear weapons is as a deterrent to their use. Others, such as Representative Mac Thornberry, argue that changes in U.S. nuclear policy could lead to a more dangerous world by undermining nuclear deterrence.