My New York Times op-ed on the possibility that China is rethinking its no-first-use pledge has already attracted a number of thoughtful responses, including from Major General Yao Yunzhu of China’s Academy of Military Sciences and M. Taylor Fravel of the Massachusetts Institute of Technology, both of whom argue that Beijing is not changing its nuclear doctrine.

I very much welcome this debate and emphasize from the outset that I hope I am wrong. Any shift away from no first use is likely to be viewed by the United States and its allies—rightly or wrongly—as provocative. So, hopefully China is indeed committed to its no-first-use policy. However, I am not entirely convinced that it is for a number of reasons, including a few that I did not have the space to elaborate on in my original op-ed.

This debate started with the publication of China’s new white paper on defense, which omits any explicit mention of China’s long-standing no-first-use pledge. Yao, Fravel, and others have emphasized that the only nuclear mission explicitly discussed in the white paper is entirely consistent with no-first use—a point I acknowledge in my original op-ed. However, no first use necessarily involves renouncing other missions, something the new white paper does not do.

Chinese officials have also emphasized that the new document has a distinctly different format from previous white papers, describing it as “thematic” as opposed to “comprehensive.” It also has a different title— “The Diversified Employment of China’s Armed Forces” as opposed to “China’s National Defense”—and is organized differently (the section on arms control and disarmament is omitted, for example).  It is argued that this new format, rather than a change in doctrine, accounts for the absence of a no-first-use commitment.

The problem with this argument is that it fails to explain why a white paper on the missions assigned to China’s armed forces would be anything other than an obvious place to repeat a commitment to no first use. Indeed, China has repeated its no-first-use pledge in “operational” sections of previous white papers, not just the sections that deal with arms control and disarmament. A 2008 white paper, for example, discusses the mission of the Second Artillery Force in terms that are very similar to those used in the new white paper, with the exception that the 2008 document includes China’s no-first-use pledge. It is hard to understand why it was appropriate to mention no first use in 2008 in a discussion of the role of the Second Artillery Force but not in a similar discussion in 2013—unless a rethink is underway. 

Interestingly, we already have a new data point. Today, at a preparatory meeting in Geneva for the 2015 Nuclear Non-Proliferation Treaty Review Conference, China’s statement did mention no first use, but in terms noticeably weaker than in previous years. China’s ambassador stated that “China has adhered to the policy of no-first use of nuclear weapons at any time or under any circumstances…” The choice of words here— “has adhered” and not “is adhering”—leaves it unclear whether the policy is still operative.

To be sure, China used virtually identical wording in the two most recent review meetings (in 2012 and 2010). However, on both of those occasions China called for all nuclear-weapon states to conclude a multilateral no-first-use treaty—a step it did not take this year. Moreover, going slightly further into the past, what China had to say about its no-first-use commitment at such meetings was entirely unambiguous. For example, in 2008 the Chinese delegate stated that “China remains firmly committed to the policy of no-first use of nuclear weapons at any time and under any circumstances.” The wording in 2007 was similar. [Editor’s note: See the comment by Iain Johnston below for a helpful note on translation.]

In the final analysis, however, it is important not to get sucked into this morass of details and instead focus on the big picture. China’s no-first-use commitment has been at the heart of its nuclear doctrine for as long as it has had nuclear weapons. Since its first nuclear test in 1964, Beijing has restated this promise in virtually every document and speech concerning nuclear weapons. Its omission from Xi Jinping’s speech to the Second Artillery Force last December and from the new white paper, therefore, demands attention. Indeed, while Yao states that China’s no-first-use policy remains in force, she also adds that “speculations on a possible change to the [no-first-use] policy have not been conjured up without reason.”

Here common ground emerges between Yao, Fravel, and myself. While we may disagree about the meaning of the new white paper and Xi’s speech, we all agree that much deeper engagement on nuclear deterrence between the United States and China is needed. Realistically, that is the only way this debate can be definitively settled.

Editor's note: This article was edited to correct minor errors.