David Logan on His Newest Publication on China's Nuclear Buildup
Dr. David Logan talks to CACR about his latest monograph on China’s nuclear buildup, the potential nuclear dynamics of a Taiwan contingency, and debates in the theoretical literature over counterforce and damage limitation strategies. This interview is edited for clarity and length. (September 6, 2023)
Dr. David C. Logan is Assistant Professor of Security Studies at the Fletcher School of Law and Diplomacy at Tufts University, where his research focuses on nuclear weapons, arms control, deterrence, and the U.S.-China security relationship. He previously taught in the National Security Affairs Department at the Naval War College and served as a Stanton Nuclear Security Fellow with the MIT Security Studies Program and a Fellow with the Princeton Center for International Security Studies, where he was also Director of the Strategic Education Initiative. Dr. Logan has conducted research for the Center for the Study of Chinese Military Affairs at National Defense University, the Defense Threat Reduction Agency, and the Office of Net Assessment. He has published in International Security, Journal of Strategic Studies, Georgetown University Press, National Defense University Press, Foreign Affairs, Los Angeles Times, and War on the Rocks, among other venues. He holds a B.A. from Grinnell College and an M.P.A., M.A., and Ph.D. from Princeton University.
You recently a published monograph on the drivers of China's nuclear buildup with Phil Saunders, Director of the Center for the Study of Chinese Military Affairs at the National Defense University. Can you tell us about that?
A lot of information has come out over the last several years about changes in the hardware that constitutes China's nuclear forces and to a somewhat lesser degree changes in the potential operations of those nuclear forces. But a lot less has come out about why these changes are taking place, the drivers, the goals, and the endpoint. A large part of that is because China has not been particularly transparent about its nuclear forces. This is a longstanding practice. They've historically had a very small, immature, and vulnerable nuclear force, and the belief was that opacity about those nuclear forces would strengthen the survivability of their deterrent because if the adversary doesn't know what you have, how many of them you have, where they are, or how they're operated, it makes it a lot harder to undermine the deterrent. So in some respect, that's just business as usual.
However, I do think it's a little bit surprising that we haven't seen an official statement about why they're developing some of these new systems. While China has always been very opaque about its nuclear hardware, it's been more transparent about the high-level goals that its nuclear forces were meant to serve and the conditions under which it might resort to nuclear use, but we haven't seen any information about why the expansion is occurring or even that it is. So we have a lot of change on the hardware side, and essentially a vacuum when it comes to declaratory policy. That means that there's a growing divergence between what China has historically said about its nuclear forces, what it would do with them and why it has them– which is very limited– and this new hardware, which is very expansive.
So the purpose of our study was to try to identify alternative methods for discerning what might be some of the underlying drivers of the expansion and modernization. The first thing we did was try to brainstorm all the competing explanations for why China could be building out its nuclear forces. The second step was to think about the identifiable characteristics of a nuclear force posture that would emerge from each of those competing explanations and to map those predicted values of the nuclear force postures onto what we see today in China's nuclear force today and what we might see tomorrow. The benchmark that we used was 2031; we thought that gave us sufficient lead time to see change in the nuclear posture, but it was also close enough in time that we could get reasonable estimates about what changes would take place. Some of those estimates come from reports put out by the US government. So one of the things you see in the study, which I think is really interesting and reinforces the whole need for this study in the first place, is that today if you look at China's nuclear force posture, even with a lot of the changes that have taken place over the last several years, it still largely looks like a force that is designed to support a strategy of assured retaliation. This is a strategy that implies a limited view about the political and military utility of nuclear weapons. That makes sense, because this is a force that has emerged over the last several years, decades even, when that was very clearly China's nuclear strategy.
When you go out to 2031, however, there's a lot more ambiguity. A lot of the other competing explanations that don't really explain China's nuclear force posture today become much more credible when you think about explaining the hypothesized nuclear force posture in 2031. I think that again highlights the uncertainty about what’s going on.
So finally, to try to get a better handle on the underlying drivers, we developed some additional observable implications to look for. If people read the report, they will see that we do find strong evidence that survivability concerns play a large role in explaining China’s nuclear force development, but we also see strong and increasing evidence for what we call the nuclear shield model, of China trying to develop a nuclear force at both the strategic and the theater levels. The purpose in that model is to create a deterrent that gives China more freedom of action at lower levels of violence to, to borrow my coauthor’s term, “make the world safe for conventional aggression.” We also find evidence of great power status drivers potentially influencing some of this decision making.
When you talk about making the world safe for conventional aggression, that evokes the Taiwan situation. Could the nuclear shield approach be an attempt to gain more latitude in a Taiwan contingency?
Yes, that is definitely one of the contingencies that of course feature heavily in PLA strategy and force development and conventional forces, and it’s hard to imagine a scenario in which nuclear weapons feature heavily that wouldn't involve a US-China confrontation or Taiwan. That’s where the stakes are highest, and the geography is such that it plays up the relevance of the People’s Liberation Army Rocket Force. There are also reports in the last several years– including in the US DOD China Military Power Report– of PLA strategists being concerned that in a conflict over Taiwan, Chinese conventional superiority might lead the United States to consider nuclear escalation first, and that perhaps some of the Chinese investments in theater nuclear capabilities are designed to offset US capabilities and deter what the PLA might view as the threat of US nuclear escalation. So yes, I think the Taiwan contingency definitely features heavily in any kind of consideration about nuclear shield.
Has China’s messaging on its No First Use policy shifted in any way?
No, I don’t think there’s been a change in the messaging. I think it's still consistent. You see references to no first use popping up in high-level statements, whether it was Chinese filings as part of the 2020 Nonproliferation Treaty (NPT) Review Conference to references in China’s Defense White papers, so I don’t think we see a change in that.
One area where we do see a change, and folks like Rod Lee at the China Aerospace Studies Institute have done a good job highlighting this, is if you look at the most recent edition of The Science of Military Strategy published by the National Defense University and compare it to previous iterations, there are two changes. One is, it appears that there are fewer references to past Chinese leaders’ views of nuclear weapons and especially the perceived limited utility of nuclear weapons within those views. And two, you see less language about restrictions on the development of Chinese nuclear forces. So, in the past, China would use the phrase “lean and effective deterrent,” talking about keeping its nuclear forces at the minimum level necessary to accomplish China’s goals in the nuclear space, and we see fewer references of that type. So there’s a little bit of a distinction there; there are fewer references to restrictions on nuclear force development. But I don’t think we see a change when talking about the actual use of those forces.
Given China’s second-strike capability, are there any Western theorists or researchers in the literature who are still writing about counterforce, as they have in past periods in the nuclear age, or has that discussion faded due to the riskiness of counterforce?
The short answer is yes. I don’t know if those advocating counterforce posturing would advocate actually launching a counterforce strike, but there’s certainly a contingent who would argue for adopting a damage limitation posture against China, which at the very least means maintaining a sufficient nuclear superiority over China so that if the time came and you felt like nuclear escalation was sufficiently likely, you could attempt to erode enough of China’s nuclear forces at the strategic level that you could reduce the damage the United States would suffer. So I don’t think it’s necessarily this belief that the United States can achieve ultimate nuclear primacy and with a hundred percent certainty eliminate the possibility of a retaliatory strike coming from China to US territory, but there are folks who believe that a damage limitation strategy is feasible and that such a strategy would not unduly increase escalation risks.
To explain a little bit about this idea of damage limitation, it demands counterforce targeting, and it demands a nuclear force and posture that would allow one side to, if not completely take out the nuclear capabilities of the other side, then at least erode them in a way that sufficiently limits the damage they can deal. What is sufficient? I don’t know. During the Cold War, the US would sometimes talk about a “recovery period” and how quickly one side could recover from a nuclear war. Both the Soviet Union and the United States would suffer tremendous damage, but if you accept that damage as inevitable, then maybe the side that can recoup more quickly is the one that would come out on top, and one of the factors that would affect how quickly you could recuperate, is just how much relative damage did you suffer. So maybe the US suffers 10 million fatalities, but that’s better than suffering 40 million, especially if that’s how much the Soviet Union is suffering.
There’s a couple of costs that come with damage limitation strategies. One is that it may reduce crisis stability. Much of the theory about nuclear weapons says you want to try to avoid a situation in which any side in a nuclear crisis or conflict or a conventional conflict involving nuclear-armed powers feels use-it-or-lose it pressures, where they fear that their nuclear forces are vulnerable and could be eradicated by the adversary and that they need to use them, or at least threaten to use them. Those threats can initiate an action-reaction spiral that can be very escalatory and dangerous. The second is that damage limitation strategies can encourage arms racing. If the US commits to a damage limitation strategy, that means that it has committed to maintaining a certain degree of superiority over China, whether it’s quantitative superiority, qualitative superiority, or supporting assets that would help facilitate a damage limitation capability. But then, of course, China can always respond, and we’re perhaps seeing some of those dynamics at play. I think again, it’s not entirely clear why China’s engaged in this buildup, but it’s fair to say that the US and the policy choices that the US government makes are at least one key factor in that decision-making calculus, and so how do you adopt a damage limitation strategy without entering into an arms race?
I am extremely skeptical of the supposed benefits of nuclear superiority. I largely ascribe to the theory of the nuclear revolution and MAD. There’s strong debates happening in the field about this right now. Over the last five years or so, there have been several books published that have really been strong critiques of the theory of the nuclear revolution and the idea that MAD is very stabilizing and can deter conflict generally. I’m oversimplifying tremendously and encourage folks to read those works for a full accounting of the arguments.
If worst came to worst and there was a conflict between the United States and China over Taiwan, would the geography of a Taiwan conflict make limited nuclear use more tempting for the Chinese leadership? In a naval context, with big bodies of open water, if you’re hitting only military targets, does that remove some of the stigma and some of the escalation concerns compared to nuclear use that impacts civilians, for example?
That’s a fantastic question. The short answer is, I don’t know. I think the logic that you spelled out makes perfect sense. But I think it depends on three things. One is the yield of the weapons. China’s deployed nuclear warheads, as far as we can tell from the open sources, are very large and not ideally suited for those kinds of warfighting missions. The smallest ones that are supposed to be deployed are 200-300 kilotons and the largest are 4-5 megatons, and those are massive. The distinction between a "tactical" and "strategic" nuclear warhead isn’t firm, but regardless, the smallest Chinese weapons are still very, very large weapons. The second question is, can China accomplish its military objectives with its conventional forces? It now has very accurate conventional ballistic missiles and the world’s largest navy and is investing in its submarine force, which all suggests that maybe it wouldn’t need nuclear weapons as much as in the past, at least to generate the kind of battlefield effects that it would want. Now, again, nuclear weapons can serve a very different political and strategic purpose than conventional weapons, so that goes back to the question of whether they could still signal, even if it is sort of overkill from a battlefield effects perspective. The third question is, even with nuclear use at sea, would there be concerns that any of that radiation would blow back over the land and whether the so-called nuclear taboo and stigma against using nuclear weapons at all could dissuade it?
I would be skeptical of China resorting to that. As far as the dominant theories about the sources of nuclear strategy today are concerned, there’s also a tradeoff between the conventional balance and the salience of nuclear use. As the local conventional balance has shifted in China’s favor, the silver lining is that it may be less likely to resort to nuclear use.