Part I:

Introduction and summary:

Since the size of the U.S. nuclear arsenal peaked in the 1980s, American presidents—Democrat and Republican alike—have limited the development of new nuclear weapons. Whether the restriction was written into law, was included in U.S. nuclear policy, or was the result of specific decisions not to pursue new procurement projects, the United States has not built a new nuclear warhead since the late 1980s. This policy decision has generated significant cost savings, restrained strategic competition, and helped to support other stabilizing policies.

With Republicans now in control of Congress and the White House, this policy is at risk. As Russia and China expand their territorial claims as well as their own nuclear arsenals, a growing chorus of U.S. politicians and strategists argue that it is not sufficient to simply replace nuclear systems as they wear out. Instead, they insist that the United States must procure new systems with qualitatively new capabilities. In some cases, appeals for new nuclear weapons are motivated by a sophisticated but mistaken argument about their necessity for deterring potential adversaries from employing nuclear weapons in limited conflicts. Other advocates endorse these programs as a way of winning future arms races or achieving supremacy over other nuclear powers.

Although it has not been specific about its plans, the Trump administration has promised to “greatly strengthen and expand its nuclear capability.”1 This seems to conflict with the assessment of Gen. John E. Hyten, the commander of U.S. Strategic Command, who has argued that “we don’t need more nuclear weapons, we just need to modernize.”2 Are the two statements consistent? What exactly is nuclear modernization? Where should the United States draw the line as it embarks on a program to replace nearly every bomb, missile, submarine, and warhead in its arsenal?

Constructive debate over these plans is often obstructed by imprecise vernacular. The term modernization is variously used to refer to existing programs that refurbish current weapons systems, existing programs that update current systems with improved versions, and to proposals that would create qualitatively new capabilities. Responsible modernization that refurbishes and replaces existing systems with improved variants is necessary in order for such systems to continue to carry out their missions safely and reliably. However, establishing programs that would enable the United States to hold targets at risk in qualitatively new ways would be destabilizing, unnecessary, and irresponsible. Specifically, developing new nuclear capabilities would likely increase global nuclear competition, accelerating a new arms race; create uncertainty for existing modernization programs in the Pentagon budget and also at the national laboratories that maintain the nuclear stockpile; increase the likelihood that new countries could seek to acquire nuclear weapons; and do little to improve the ability of the U.S. armed forces to deter and defend against aggression around the world. 

As the new administration begins its Nuclear Posture Review, the decades-old bipartisan prohibition against the development of new nuclear capabilities is more important than ever. This analysis is informed by a table top exercise that was carried out at the Centre for American Progress in the autumn of 2016. In it, a bipartisan group of former officials and experts in nuclear weapons policy—including both proponents and opponents of new nuclear options—investigated the role of U.S. nuclear forces in the defence of NATO’s Baltic members. Although the participants were not asked to endorse the findings of this report, their deliberations are instructive in evaluating the case for new nuclear weapons.

To be continued: