Assessing the U.S. Need for Retaining a Nuclear First Strike Option In the Current International Security Climate

Abstract

Retaining the option to use nuclear weapons first in conflict has been a recurring theme in U.S. nuclear weapons policy. The 2010 Nuclear Posture Review deliberately leaves open the option for the United States to use nuclear weapons first under “extreme circumstances.” The purpose of this paper is to evaluate these “extreme circumstances” and determine whether the United States can safely take the first-use option off the table, thereby reducing the role of nuclear weapons in its national security strategy. To that end, the central question of this thesis is whether there are any realistic military contingencies today that would justify maintaining a possible first-use nuclear doctrine. I explore three reasons why the United States might decide to threaten, or actually use, nuclear weapons first: 1. To deter or respond to conventional aggression 2. To deter or respond to chemical or biological attacks 3. To pre-empt an adversary’s use of nuclear weapons While there has not been a third world war in the nuclear age, there is a significant positive association between nuclear weapons possession and lower-level conflicts. Moreover, given U.S. conventional superiority, the U.S. does not need nuclear weapons to counter conventional aggression. Because nuclear first use would bring disproportionate destruction in such low-level conventional conflicts, such threats would not be credible. A nuclear first strike would only be appropriate (and credible) in a situation in which the United States or an ally was facing an existential threat. These conditions are few and improbable, and the need for nuclear first use threats can be mitigated through other means. For instance, developing defense measures that reduced the impact of chemical and biological attacks may be a more credible deterrent to actors considering such attacks than the threat of nuclear retaliation. Failing this, the United States would be capable of a large-scale conventional attack that would be a more proportionate response to a chemical or biological attack. In the case of a terrorist chemical or biological attack, threatening a response with technologies such as unmanned aerial systems that are capable of more surgical strikes may be a more effective deterrent than nuclear weapons. Though a nuclear strike may currently be the only option to preemptively counter an imminent nuclear attack by an adversary, the intelligence and operational challenges are too great to risk the consequences of pre-emptive action. In a severe crisis, the continued option to use nuclear weapons first risks creating instabilities that increase the chances of miscalculation, misunderstandings and escalation. The impact of U.S. declaratory policy should not be underestimated and a no-first-use (NFU) declaration may contribute significantly to strategic stability. For those who find NFU too constraining and worry about the impact on allies, an alternative, intermediary policy is proposed at the end of this paper that could be a step in the direction of NFU. It would allow the U.S. to respond – but not preemptively – to large-scale non-nuclear aggression with nuclear weapons, but only when its or its allies’ survival was at stake. If the United States is committed to reducing nuclear dangers, NFU (or at the very least, a declaratory policy raising the threshold for first use) should be one of the first necessary changes in U.S. nuclear policy.