Washington and Moscow hold the keys to the door of disarmament

The disarmament momentum created by Barack Obama's famous Prague speech was fading even before Donald Trump won the race to become Obama's successor. Now, prospects for disarmament seem murkier than ever. It is an interesting moment to take up my roundtable colleague Gregory Kulacki's argument that China, by displaying too much reluctance to implement its disarmament obligations, undermines its own image and squanders an opportunity to assume a leading role in global governance.

For decades China has taken seriously its disarmament obligations under the Nuclear Non-Proliferation Treaty (NPT). In fact, Beijing called for total abolition of nuclear weapons upon conducting its first nuclear test five decades ago. Disarmament serves China's long-term interests—but Beijing faces an increasingly complicated security environment and maintains a relatively small nuclear deterrent. So China will only be able to achieve disarmament by taking a cautious and pragmatic approach.

Disarmament stalemate. Since the end of the Cold War, the United States and Russia have significantly reduced their bloated nuclear arsenals through arms control agreements and unilateral cuts. Unfortunately, the cuts have only been designed to "optimize" the two sides' arsenals; Washington and Moscow haven't made the deep cuts that could induce other nuclear powers to join the process. As a result, the global nuclear inventory remains huge, amounting to about 15,000 warheads, with the United States and Russia accounting for 93 percent of them.

Worse, the United States has steadily developed missile defense and conventional prompt strike capabilities as part of its strategic forces. This puts at risk small nuclear deterrents such as China's, causing Beijing to rely more heavily on its nuclear deterrent and decreasing China's incentives to engage in disarmament. At the moment, the keys to the door of disarmament remain in American and Russian hands.

China's unique outlook. The commitment to disarm under the NPT is both normative and legally binding. But the commitment alone doesn't provide nuclear weapon states a sufficient incentive to disarm. Nations won't perceive a sufficient incentive until disarmament can accommodate their national views on the utility of nuclear weapons and on those weapons' role in national security.

Throughout the Cold War, nuclear weapons were at the core of US and Russian security strategies, and mutual assured destruction prevented each side from attacking the other. China's outlook was different. Even though China joined the nuclear club in 1964 amid severe security concerns, Mao Zedong viewed nuclear weapons as a "paper tiger." This view had a profound influence on China's nuclear weapons development and nuclear posture. Indeed, it took decades for Beijing to develop its small arsenal and to make its nuclear deterrent truly operational. China was the first state to announce an intention to disarm at the same time it successfully developed nuclear weapons—and to proclaim a nuclear no-first-use policy. Disarmament, no matter whether you consider it obligatory or optional, fits China's nuclear philosophy.

To be sure, the role of nuclear weapons is increasing in China's security calculations. But the "non-usefulness" of these weapons in actual warfighting prevents China from developing a large arsenal, let alone from seeking parity with larger nuclear powers. And with the emergence of nuclear-armed states along China's periphery, disarmament and nonproliferation are clearly in Beijing's long-term national interest.

China may not have taken substantial steps toward disarmament so far but—despite what Kulacki believes—this doesn't mean that China is reluctant to meet its obligations under the treaty. Rather, China is following its own path toward disarmament. What does this path entail? First, disarmament can't be pursued simply by reducing numbers of warheads and missiles; the superior quality of US and Russian weapons must be considered as well. Second, China sees ratification of the Comprehensive Nuclear Test Ban Treaty and negotiation of a Fissile Material Cutoff Treaty as important steps toward disarmament—but these treaties should be negotiated and ratified along with an instrument to outlaw the first use of nuclear weapons. Third, because missile defense and conventional military capabilities can provide nations an incentive to develop or expand a nuclear arsenal, they should be included on the disarmament agenda as well.

Yes, China has a responsibility to implement its disarmament commitments more proactively. But nuclear powers must seek disarmament through—to borrow a phrase usually associated with climate change negotiations—the principle of common but differentiated responsibilities. With luck, China can work with the next US administration, as well as with other nuclear-armed nations, to make the next NPT review conference a substantive one.