The U.S. Nuclear Posture Review and Nuclear War in Asia

The Trump administration has issued its 2018 Nuclear Posture Review (NPR), a 100-page document that highlights the geostrategic threat environment facing the United States today, the role of nuclear weapons in securing the U.S. homeland and interests, and a range of tailored strategies to counter adversaries.

Contrary to what proponents of the document have to say, the 2018 NPR is not a status quo document. While it could charitably be seen as a posture document that may have been issued by any Republican administration – and it doesn't particularly carry any Trumpian characteristics, such as calling for an abrogation of existing arms reduction commitments and massively increasing the size of the U.S. arsenal – the document includes several important policy changes.

One of these changes involves the United States' declaratory policy, which addresses the circumstances under which the country would use its nuclear weapons. The 2018 NPR threatens nuclear use against adversaries who might undertake “significant non-nuclear strategic attacks,” including cyberattacks on the U.S. and its allies, or even cyberattacks on U.S. nuclear “command and control, or warning and attack assessment capabilities.” (The NPR nonetheless maintains that the United States will not use nuclear weapons against non-nuclear adversaries, an important cornerstone of promoting the nonproliferation of nuclear weapons.)

The 2018 NPR calls for the United States to develop and deploy two new nuclear weapons “to enhance the flexibility and responsiveness of U.S. nuclear forces.” Both systems involve lower-yield options – a response to what the NPR's framers see as a vast discrepancy between Russia's 2,000-some nonstrategic nuclear weapons and the United States' more limited options. The United States today does deploy multiple systems capable of delivering nuclear yields as low as 0.3 kilotons (yes, 300 tons of TNT equivalent). Three mods of the B61 gravity bomb and the nuclear-armed air-launched cruise missile (ALCM) can deliver low yields; all these systems are deliverable by air only and both are undergoing modernization.

The first new system the NPR calls for is a low-yield warhead for the existing U.S. arsenal of Trident D5 submarine-launched ballistic missiles (SLBMs); the D5s currently serve as the tip of the spear for the United States' sea-based deterrent, with the existing W76 and W88 warheads on these SLBMs designed for strategic retaliation only. The 2018 NPR calls for a low-yield variant of the W76, presumably to use against low-level Russian aggression. (The NPR’s framers offer no answer for the serious problems that arise from mixing strategic and substrategic warheads on the United States' existing SLBMs.)

The second capability the 2018 NPR calls for is a new sea-launched cruise missile that could be deployed on existing U.S. Navy surface ships or nuclear attack submarines (SSNs). This system would be a spiritual successor to the nuclear Tomahawk, which the United States officially retired in 2013 after the Obama administration's 2010 NPR saw no use for the capability any longer. In reality, the nuclear Tomahawk was withdrawn from deployment in the early 1990s, after President George H.W. Bush's Presidential Nuclear Initiatives – a post-Cold War unilateral decision to draw down forward-deployed low-yield nuclear weapons.

When it comes to adversaries, the NPR’s framers have four in mind: Russia, China, North Korea, and Iran. (Iran, curiously, is the only adversary that has neither a nuclear weapons capability nor intercontinental-range ballistic missile capability.) While Russia, as the only state to have a nuclear arsenal comparable to that of the United States in size, receives a bulk of the attention in the NPR, China and North Korea receive considerable focus as well. Pyongyang's breakneck advances in 2017, which included its first-ever demonstrations of an intercontinental-range ballistic missile capability and a claimed two-stage thermonuclear bomb, win it two more mentions than China in the document, in fact.

When it comes to the so-called “tailored” strategies presented in the NPR for North Korea and China, there's little new or original to be found. On North Korea, the NPR notes that the United States will continue to field nuclear weapons to strike “hardened and deeply buried facilities” that are important for the Kim Jong-un regime's survival in a conflict and also host North Korean command and control facilities. The NPR notes that conventional capabilities may be used to this end as well. Missile defense receives some attention, but this will be addressed in more detail in the Trump administration's upcoming Missile Defense Review.

The NPR's inputs on North Korea aren't particularly concerning, since the country is far from a peer state to the United States. Washington maintains overwhelming nuclear and conventional superiority over Pyongyang. What is most interesting for observers of Asia is the NPR's framing of the deterrent relationship with China. While acknowledging that China maintains the same declaratory nuclear posture it has had for decades – no first use with a force structure intended to assure retaliation – the NPR expresses concern about China's long-term intentions.

“Our tailored strategy for China is designed to prevent Beijing from mistakenly concluding that it could secure an advantage through the limited use of its theater nuclear capabilities or that any use of nuclear weapons, however limited, is acceptable,” the NPR notes. While Chinese modernization is ongoing and Beijing has deployed four nuclear-powered ballistic missile submarines (SSBNs), the NPR does not offer a theory of why Beijing may shift to consider first use of nuclear weapons viable in a conflict.

China made its thoughts clear about the 2018 NPR immediately. A spokesperson for the Chinese Ministry of Defense said it rejected the report's characterization of China's intentions. The spokesperson affirmed China's long-time declaratory nuclear posture of no first use. “We hope the U.S. side will discard its ‘cold-war mentality,’ shoulder its own special and primary responsibility for nuclear disarmament, understand correctly China’s strategic intentions and take a fair view on China’s national defense and military development,” the spokesperson added.

Since the NPR’s release, budgets released by the U.S. National Nuclear Security Administration and the U.S. Department of Defense have made clear that work on the two new capabilities will begin right away. The Trump administration’s NPR ultimately will do little to alter deterrent relationships between the United States and its two identified adversaries in Asia. Moreover, the document offers little insight beyond boilerplate language into sustained nuclear extended deterrence toward Japan and South Korea when North Korea's newfound ICBM capabilities introduce the threat of alliance decoupling to Northeast Asia.

The administration had an opportunity with this NPR to potentially acknowledge mutual vulnerability with China – a stabilizing development – or set out a path on bilateral arms control on new and destabilizing technologies, like nuclear-capable hypersonic systems. Instead, it chose to predictably pursue new capabilities that fill nonexistent capability gaps and shift U.S. declaratory policy in a dangerous new direction. In Pyongyang and Beijing, the 2018 NPR is simply a vindication of longstanding skepticism about U.S. intentions.