Tag Archives: nuclear weapons

You Can’t Put the Nuclear Cat Back in the Bag

Defense Secretary James Mattis has called for relief to North Korea to only come after it takes “irreversible steps to denuclearization.”

Let’s set aside the question of whether this will happen. It probably won’t. The United States cannot credibly commit to not invade a nuclear-free North Korea under the right circumstances, and so North Korea will keep its deterrent to hedge against that. And even if that credible commitment were not a concern, the ability to build nuclear weapons drives concessions. North Korea would not agree to “irreversible” denuclearization if only to maintain its ability to leverage the threat to build again.

Instead, let’s focus on a more interesting question: can you make nuclear proliferation irreversible? This is difficult to answer because you first need to somehow quantify a state’s nuclear proficiency. One cannot observe proficiency directly, only behaviors consistent with low or high proficiency.

Fortunately, Brad Smith and I have developed a measure of this. ν-CLEAR takes observable nuclear behaviors and uses that information to estimate a country’s nuclear proficiency. We are currently working on a massively expanded version of the data, and one of our findings speaks to the situation with North Korea.

Consider the role of uranium enrichment and reprocessing on nuclear proliferation. This is a critical step toward actually building a nuclear weapon. Bombs need fuel, and to have fuel you need to either enrich uranium or reprocess plutonium from spent uranium. The Yongbyon Nuclear Scientific Research Center has such a facility. Any deal like what the Trump administration hopes for would involve shutting this down.

However, shutting down a facility does not necessarily make nuclear proliferation irreversible. Unless actually operating an enrichment or reprocessing facility radically shifts a country’s nuclear proficiency, North Korea could just construct a new one.

Our data and a little bit of historical knowledge can help us understand the relationship between fuel facilities and nuclear proficiency. Argentina operated its Pilcaniyeu Enrichment Facility until 1994. Let’s look at a timeline of Argentina’s nuclear proficiency before and after. Larger values mean greater proficiency:

Closing the facility had an effect. But it’s marginal. Let’s zoom in on 1994:

Argentina’s proficiency score definitely drops. However, operating the facility is only of marginal importance.

What is going on here? The issue is that having a facility and knowing how to create a facility are two different things. A country that builds fuel fabrication centers also has the nuclear capacity to engage in other nuclear activities. Our estimation procedure incorporates those factors into a state’s overall score. When a state shuts down those facilities, the procedure penalizes that state’s score. But it also recognizes the state’s other nuclear activities as evidence of its ability to rebuild a facility if it wanted to. As a result, ν does not believe that operation of the facility tells us much about what Argentina can or cannot do.

Bringing this back to North Korea, it is unlikely that any sort of divestment will irreversibly cancel North Korea’s nuclear weapons program. For these purposes, knowing how to do things is more important than actually doing them. As long as North Korean nuclear scientists retain their knowledge, Peongyang will always be able to restart the program.

As a final note, to be clear, I am not suggesting that the U.S. should ignore the importance of the Yongbyon Nuclear Scientific Research Center. When Donald Trump meets Kim Jong-un, it should be an important topic of discussion. The ν measure only captures what states can do. It does not care much about time delays. Shuttering Yongbyon would probably not reduce North Korea’s ability to develop more fuel. But it would increase the time necessary to do that because North Korea would have to rebuild the facility. And that’s a goal worth obtaining.

Does Increasing the Costs of Conflict Decrease the Probability of War?

According to many popular theories of war, the answer is yes. In fact, this is the textbook relationship for standard stories about why states would do well to pursue increased trade ties, alliances, and nuclear weapons. (I am guilty here, too.)

It is easy to understand why this is the conventional wisdom. Consider the bargaining model of war. In the standard set-up, one side expects to receive p portion of the good in dispute, while the other receives 1-p. But because war is costly, both sides are willing to take less than their expected share to avoid conflict. This gives rise to the famous bargaining range:

Notice that when you increase the costs of war for both sides, the bargaining range grows bigger:

Thus, in theory, the reason that increasing the costs of conflict decreases the probability of war is because it makes the set of mutually preferable alternatives larger. In turn, it should be easier to identify one such settlement. Even if no one is being strategic, if you randomly throw a dart on the line, additional costs makes you more likely to hit the range.

Nevertheless, history often yields international crises that run counter to this logic like trade ties before World War I. Intuition based on some formalization is not the same as solving for equilibrium strategies and taking comparative statics. Further, while it is true that increasing the costs of conflict decrease the probability of war for most mechanisms, this is not a universal law.

Such is the topic of a new working paper by Iris Malone and myself. In it, we show that when one state is uncertain about its opponent’s resolve, increasing the costs of war can also increase the probability of war.

The intuition comes from the risk-return tradeoff. If I do not know what your bottom line is, I can take one of two approaches to negotiations.

First, I can make a small offer that only an unresolved type will accept. This works great for me when you are an unresolved type because I capture a large share of the stakes. But if also backfires against a resolved type—they fight, leading to inefficient costs of war.

Second, I can make a large offer that all types will accept. The benefit here is that I assuredly avoid paying the costs of war. The downside is that I am essentially leaving money on the table for the unresolved type.

Many factors determine which is the superior option—the relative likelihoods of each type, my risk propensity, and my costs of war, for example. But one under-appreciated determinant is the relative difference between the resolved type’s reservation value (the minimum it is willing to accept) and the unresolved type’s.

Consider the left side of the above figure. Here, the difference between the reservation values of the resolved and unresolved types is fairly small. Thus, if I make the risky offer that only the unresolved type is willing to accept (the underlined x), I’m only stealing slightly more if I made the safe offer that both types are willing to accept (the bar x). Gambling is not particularly attractive in this case, since I am risking my own costs of war to attempt to take a only a tiny additional amount of the pie.

Now consider the right side of the figure. Here, the difference in types is much greater. Thus, gambling looks comparatively more attractive this time around.

But note that increasing the military/opportunity costs of war has this precise effect of increasing the gap in the types’ reservation values. This is because unresolved types—by definition—view incremental increases to the military/opportunity costs of war as larger than the resolved type. As a result, increasing the costs of conflict can increase the probability of war.

What’s going on here? The core of the problem is that inflating costs simultaneously exacerbates the information problem that the proposer faces. This is because the proposer faces no uncertainty whatsoever when the types have identical reservation values. But increasing costs simultaneously increases the bandwidth of the proposer’s uncertainty. Thus, while increasing costs ought to have a pacifying effect, the countervailing increased uncertainty can sometimes predominate.

The good news for proponents of economic interdependence theory and mutually assured destruction is that this is only a short-term effect. In the long term, the probability of war eventually goes down. This is because sufficiently high costs of war makes each type willing to accept an offer of 0, at which point the proposer will offer an amount that both types assuredly accept.

The above figure illustrates this non-monotonic effect, with the x-axis representing the relative influence of the new costs of war as compared to the old. Note that this has important implications for both economic interdependence and nuclear weapons research. Just because two groups are trading with each other at record levels (say, on the eve of World War I) does not mean that the probability of war will go down. In fact, the parameters for which war occurs with positive probability may increase if the new costs are sufficiently low compared to the already existing costs.

Meanwhile, the figure also shows that nuclear weapons might not have a pacifying effect in the short-run. While the potential damage of 1000 nuclear weapons may push the effect into the guaranteed peace region on the right, the short-run effect of a handful of nuclear weapons might increase the circumstances under which war occurs. This is particularly concerning when thinking about a country like North Korea, which only has a handful of nuclear weapons currently.

As a further caveat, the increased costs only cause more war when the ratio between the receiver’s new costs and the proposer’s costs is sufficiently great compared to that same ratio of the old costs. This is because if the proposer faces massively increased costs compared to its baseline risk-return tradeoff, it is less likely to pursue the risky option even if there is a larger difference between the two types’ reservation values.

Fortunately, this caveat gives a nice comparative static to work with. In the paper, we investigate relations between India and China from 1949 up through the start of the 1962 Sino-Indian War. Interestingly, we show that military tensions boiled over just as trade technologies were increasing their costs for fighting; cooler heads prevailed once again in the 1980s and beyond as potential trade grew to unprecedented levels. Uncertainty over resolve played a big role here, with Indian leadership (falsely) believing that China would back down rather than risk disrupting their trade relationship. We further identify that the critical ratio discussed above held—that is, the lost trade—evenly impacted the two countries, while the status quo costs of war were much smaller for China due to their massive (10:1 in personnel alone!) military advantage.

Again, you can view the paper here. Please send me an email if you have some comments!

Abstract. International relations bargaining theory predicts that increasing the costs of war makes conflict less likely, but some crises emerge after the potential costs of conflict have increased. Why? We show that a non-monotonic relationship exists between the costs of conflict and the probability of war when there is uncertainty about resolve. Under these conditions, increasing the costs of an uninformed party’s opponent has a second-order effect of exacerbating informational asymmetries. We derive precise conditions under which fighting can occur more frequently and empirically showcase the model’s implications through a case study of Sino-Indian relations from 1949 to 2007. As the model predicts, we show that the 1962 Sino-Indian war occurred after a major trade agreement went into effect because uncertainty over Chinese resolve led India to issue aggressive screening offers over a border dispute and gamble on the risk of conflict.

Understanding the Iran Deal: A Model of Nuclear Reversal

Most of the discussion surrounding the Joint Comprehensive Plan of Action (JCPOA, or the “Iran Deal”) has focused on mechanisms that monitor Iranian compliance. How can we be sure Iran is using this facility for scientific research? When can weapons inspectors show up? Who gets to take the soil samples? These kinds of questions seem to be the focus.

Fewer people have noted Iran’s nuclear divestment built into the deal. Yet Iran is doing a lot here. To wit, here are some of the features of the JCPOA:

  • At the Arak facility, the reactor under construction will be filled with concrete, and the redesigned reactor will not be suitable for weapons-grade plutonium. Excess heavy water supplies will be shipped out of the country. Existing centrifuges will be removed and stored under round-the-clock IAEA supervision at Natanz.
  • The Fordow Fuel Enrichment Plant will be converted to a nuclear, physics, and technology center. Many of its centrifuges will be removed and sent to Natanz under IAEA supervision. Existing cascades will be modified to produce stable isotopes instead of uranium hexafluoride. The associated pipework for the enrichment will also be sent Natanz.
  • All enriched uranium hexafluoride in excess of 300 kilograms will be downblended to 3.67% or sold on the international market.

Though such features are fairly common in arms agreements, they are nevertheless puzzling. None of this makes proliferation impossible, so the terms cannot be for that purpose. But they clearly make proliferating more expensive, which seems like a bad move for Iran if it truly wants to build a weapon. On the other hand, if Iran only wants to use the proliferation threat to coerce concessions out of the United States, this still seems like a bad move. After all, in bargaining, the deals you receive are commensurate with your outside options; make your outside options worse, and the amount of stuff you get goes down as well.

The JCPOA, perhaps the worst formatted treaty ever.

The JCPOA, perhaps the most poorly formatted treaty ever.

What gives? In a new working paper, I argue that undergoing such a reversal works to the benefit of potential proliferators. Indeed, potential proliferators can extract the entire surplus by divesting in this manner.

In short, the logic is as follows. Opponents (like the United States versus Iran) can deal with the proliferation problem in one of two ways. First, they can give “carrots” by striking a deal with the nuclearizing state. These types of deals provide enough benefits to potential proliferators that building weapons is no longer profitable. Consequently, and perhaps surprisingly, they are credible even in the absence of effective monitoring institutions.

Second, opponents can leverage the “stick” in the form of preventive war. The monitoring problem makes this difficult, though. Sometimes following through on the preventive war threat shuts down a real project. Sometimes preventive war just a bluff. Sometimes opponents end up fighting a target that was not even investing in proliferation. Sometimes the potential proliferator can successfully and secretly obtain a nuclear weapon. No matter what, though, this is a mess of inefficiency, both from the cost of war and the cost of proliferation.

Naturally, the opponent chooses the option that is cheaper for it. So if the cost of preventive war is sufficiently low, it goes in that direction. In contrast, if the price of concessions is relatively lower, carrots are preferable.

Note that one determinant of the opponent’s choice is the cost of proliferating. When building weapons is cheap, the concessions necessary to convince the potential proliferator not to build are very high. But if proliferation is very expensive, then making the deal looks very attractive to the opponent.

This is where nuclear reversals like those built into the JCPOA come into play. Think about the exact proliferation cost that flips the opponent’s preference from sticks to carrots. Below that line, the inefficiency weighs down everyone’s payoff. Right above that line, efficiency reigns supreme. But the opponent is right at indifference at this point. Thus, the entire surplus shifts to the potential proliferator!

The following payoff graph drives home this point. A is the potential proliferator; B is the opponent; k* is the exact value that flips the opponent from the stick strategy to the carrot strategy:

Making proliferation more difficult can work in your favor.

Making proliferation more difficult can work in your favor.

If you are below k*, the opponent opts for the preventive war threat, weighing down everyone’s payoff. But jump above k*, and suddenly the opponent wants to make a deal. Note that everyone’s payoff is greater under these circumstances because there is no deadweight loss built into the system.

Thus, imagine that you are a potential proliferator living in a world below k*. If you do nothing, your opponent is going to credibly threaten preventive war against you. However, if you increase the cost of proliferating—say, by agreeing to measures like those in the JCPOA—suddenly you make out like a bandit. As such, you obviously divest your program.

What does this say about Iran? Well, it indicates that a lot of the policy discussion is misplaced for a few of reasons:

  1. These sorts of agreements work even in the absence of effective monitoring institutions. So while monitoring might be nice, it is definitely not necessary to avoid a nuclear Iran. (The paper clarifies exactly why this works, which could be the subject of its own blog post.)
  2. Iranian refusal to agree to further restrictions is not proof positive of some secret plan to proliferate. Looking back at the graph, note that while some reversal works to Iran’s benefit, anything past k* decreases its payoff. As such, by standing firm, Iran may be playing a delicate balancing game to get exactly to k* and no further.
  3. These deals primarily benefit potential proliferators. This might come as a surprise. After all, potential proliferators do not have nuclear weapons at the start of the interaction, have to pay costs to acquire those weapons, and can have their efforts erased if the opponent decides to initiate a preventive war. Yet the potential proliferators can extract all of the surplus from a deal if they are careful.
  4. In light of (3), it is not surprising that a majority of Americans believe that Iran got the better end of the deal. But that’s not inherently because Washington bungled the negotiations. Rather, despite all the military power the United States has, these types of interactions inherently deal us a losing hand.

The paper works through the logic of the above argument and discusses the empirical implications in greater depth. Please take a look at it; I’d love to hear you comments.

Bargaining Power and the Iran Deal

Today’s post is not an attempt to give a full analysis of the Iran deal.[1] Rather, I just want to make a quick point about how the structure of negotiations greatly favors the Obama administration.

Recall the equilibrium of an ultimatum game. When two parties are trying to divide a bargaining pie and one side makes a take-it-or-leave-it offer, that proposer receives the entire benefit from bargaining. In fact, even if negotiations can continue past a single offer, as long as a single person controls all of the offers, the receiver still receives none of the surplus.

This result makes a lot of people feel uncomfortable. After all, the outcomes are far from fair. Fortunately, in real life, people are rarely constrained in this way. If I don’t like the offer you propose me, I can always propose a counteroffer. And if you don’t like that, nothing stops you from making a counter-counteroffer. That type of negotiations is called Rubinstein bargaining, and it ends with a even split of the pie.

In my book on bargaining, though, I point out that there are some prominent exceptions where negotiations take the form of an ultimatum game. For example, when returning a security deposit, your former landlord can write you a check and leave it at that. You could try suggesting a counteroffer, but the landlord doesn’t have to pay attention—you already have the check, and you need to decide whether that’s better than going to court or not. This helps explain why renters often dread the move out.

Unfortunately for members of Congress, “negotiations” between the Obama administration and Congress are more like security deposits than haggling over the price of strawberries at a farmer’s market. If Congress rejects the deal (which would require overriding a presidential veto), they can’t go to Iran and negotiate a new deal for themselves. The Obama administration controls dealings with Iran, giving it all of the proposal power. Bargaining theory would therefore predict that the Obama administration will be very satisfied[2], while Congress will find the deal about as attractive as if there were no deal at all.

And that’s basically what we are seeing right now. Congress is up in arms over the deal (hehe). They are going to make a big show about what they claim is an awful agreement, but they don’t have any say about the terms beyond an up/down vote. That—combined with the fact that Obama only needs 34 senators to get this to work—means that the Obama administration is going to receivea very favorable deal for itself.

[1] Here is my take on why such deals work. The paper is a bit dated, but it gets the point across.

[2] I mean that the Obama administration will be very satisfied by the deal insofar as it relates to its disagreement with Congress. It might not be so satisfied by the deal insofar as it relates to its disagreement with Iran.

New Version of “War Exhaustion and the Credibility of Arms Treaties”

I just updated the manuscript as a standalone paper. Here’s the abstract:

Why do some states agree to arms treaties while others fail to come to terms? I argue that the changing credibility of preventive war is an important determinant of arms treaty stability. If preventive war is never an option, states can reach settlements that both prefer to costly arms construction. However, if preventive war is incredible today but will be credible in the future, a commitment problem results: the state considering investment faces a “window of opportunity” and must build the arms or it will not receive concessions later on. Thus, arms treaties fail under these conditions. I then apply the theoretical findings to the Soviet Union’s decision to build nuclear weapons in 1949. War exhaustion made preventive war incredible for the United States immediately following World War II, but lingering concerns about future preventive action caused Moscow to proliferate.

Download the full paper here.

Is the Ukrainian Nuclear Threat Enough?

Some Ukrainian officials are warning that recent Russian transgressions might force Ukraine to revisit its nuclear weapons program. From a historical perspective, this is understandable. Ukraine signed the Nuclear Nonproliferation Treaty in the mid-1990s in exchange for subsidies and territorial guarantees from the United States and Russia. Russia, seeing a target of opportunity in Crimea, subsequently violated the terms.

Yet these hawkish proclamations are just that: hawkish. They overlook nuclear realities. Ukraine did not pursue nuclear technology following its independence because such a program would have been prohibitively expensive. (And, despite what seems to be conventional wisdom on the subject, Ukraine did not really inherit nuclear weapons.) While Ukraine appears to be in a stronger economic position today, the country is going through so much domestic turmoil at the moment that Kiev’s marginal dollar is probably not best spent embarking on an atomic mission.

But does that mean nuclear weapons are irrelevant to the crisis? Absolutely not. Make no mistake: Ukraine could develop a nuclear weapon given enough time, effort, and angry declarations from the United States and Russia. If Russia made further encroachments on Ukrainian turf–beyond the Crimean target of opportunity–nuclear weapons would stop looking ridiculous and start looking desirable.

However, Putin knows this. He also knows that inducing Ukraine to proliferate is ultimately not in Russia’s best security interests. And he knows that Ukraine would also like to avoid proliferating because of the enormous costs.

These preferences and constraints are common, and I study them formally in my book project on bargaining over proliferation. In such a scenario, states negotiate settlements and avoid nuclear development. Potential nuclear powers do not want to build because they are already receiving a desirable share of the settlement. Rivals do not want to drive a harder bargain because doing so would trigger proliferation; settlement, on the other hand, means they can extract the surplus created by the potential nuclear power avoiding atomic development. Both sides win.

I suspect the Ukraine/Russia crisis will end like this. Russia will not push Ukraine much further.* Ukraine will not develop nuclear weapons, but the threat to do so will give them a better share of the deal.

Interestingly, the potential for nuclear weapons is almost as useful as the nuclear weapons themselves.

*At least until another target of opportunity arises, anyway.

ISA 2014 Presentation: War Exhaustion and the Stability of Arms Treaties

If you are interested in nuclear weapons and negotiations with Iran, consider my panel at ISA. The panel title is “TD09: Solving Puzzles with Formal Models: A Panel in Honor of Dina Zinnes” and will be on Thursday at 4 pm. (The lineup is impressive: Dina Zinnes, Kelly Kadera, Mark Crescenzi, Songying Fang, Anne Sartori, and T. Clifton Morgan.) Here’s the abstract:

Why are some arms treaties broken while others remain stable over the long term? This chapter argues that the changing credibility of launching preventive war is an important determinant of arms treaty stability. If preventive war is never an option, states can reach settlements that both prefer to costly arms construction. However, if preventive war is incredible today but will be credible in the future, a commitment problem results: the state considering investment must build the arms or it will not receive concessions later on. Thus, arms treaties fail under these conditions. The chapter then applies the theoretical findings to the Soviet Union’s decision to build nuclear weapons in 1949 and Iran’s ongoing nuclear program today. In both instances, war exhaustion made preventive war incredible for the United States, but lingering concerns about future preventive war caused both states to pursue proliferation.

You can download the full paper here.

Ukraine Was a Nuclear Power. Just Like Nebraska Is.

There are way, way too many articles, blogs, and commentaries about Ukraine right now, and a lot of them like to talk about how things would be different had Ukraine kept its nuclear weapons twenty-some years ago. I wrote about this last week, but here is a firmer response: Ukraine never had command control over nuclear weapons.

You wouldn’t know that by reading most of these articles, of course. There seems to be a large amount of historical illiteracy here, and editors aren’t doing sufficient fact checking. But to call Ukraine a former nuclear power would be like saying Nebraska is a nuclear power today or would be a nuclear power if it declared independence tomorrow. Yes, Nebraska would have a lot of nuclear weapons on their sovereign soil. But they wouldn’t have command control over the missiles. All told, they would really only have large chunks of metal holding radioactive materials. That is not the same thing as being a nuclear power, which would seem to imply the ability to…I don’t know…nuke someone.

So, media of the world, please stop saying how Ukraine made a mistake in giving up nuclear weapons. They were never theirs to give up–they just let Russian officials safely dismantle them and ship them back to Russia…which is pretty much what you would expect a country to do if it suddenly found large chunks of metal with radioactive material inside.

Crimea and Ukrainian Nuclear Nonsense

For whatever reason, it seems trendy to blame Ukraine’s current predicament on its 1994 decision to denuclearize. If Ukraine had proliferated, the logic goes, then Russia would not have invaded Crimea, and people in Kiev would be a lot happier.

The trouble is, none of this makes any sense. To be kind, these arguments rely on an awkward reading of history and assume that nuclear weapons are a magical cure-all. The issues are threefold:

1) Ukraine never had command control over nuclear weapons. Yes, there were a lot of nuclear weapons sitting on Ukrainian soil–the third most in the world at that time after the United States and Russia. But having weapons on your soil is meaningless unless you can authorize their use. Trying to obtain control over those weapons would have required force and therefore war with Russia, which, as Anton Strezhnev points out, would not have made much sense for Ukraine. At no point in time could leaders in Kiev flip a magic switch and turn on a nuclear deterrent.

So if Ukraine wanted nuclear weapons, it was going to have to work hard for them. Trouble is…

2) Building its own nuclear deterrent would have been insane. Fresh off the fall of the Soviet Union, the Ukrainian economy was hurting. Spending tons of money developing its own nuclear weapons program would have put the country in a much deeper red hole. Still, because deterrence had value, Ukraine used the nuclear issue to extract financial compensation from the West. Meanwhile, Russia offered to ship Ukraine downblended uranium to keep their nuclear power plants firing. (There were also territorial agreements that Russia is currently violating, but no one at the time reasonably believed that those terms would hold up during exceptional situations.) Nuclearization would have killed those inducements and perhaps put Ukraine in such economic peril that it seems doubtful that we would have wound up in the position we are in today.

And even if the Ukrainian economy miraculously healed and we somehow managed to find ourselves in the duplicate situation…

3) It isn’t clear how nuclear weapons would have deterred Russia. Let’s not forget Russia has a nuclear stockpile as well. It is hard to see how Ukraine could have credibly threatened nuclear retaliation in response to the invasion of Crimea. Nuclear weapons are great at deterring aggression toward vital assets. I am not sure that Crimea counts, especially since it has such heavy Russian population. A nuclear deterrent might stop Putin from pushing further west toward Kiev, but he might very well be stopping where he is anyway due to conventional threats and economic warfare from the West.

TL;DR: It is really hard to claim that Ukraine’s decision to not proliferate in the 1990s was a mistake.

Does Nuclear “Prestige” Prevent Nonproliferation Agreements?

In a word, no.

First, a brief background. The main theoretical chapter of my dissertation shows that nonproliferation agreements are fairly easy to establish. Even if a potential rising state proliferates, it will ultimately only be able to receive some amount of concessions from a rival. As such, to deter proliferation, the rival only needs to offer most of the concessions the rising state would receive if it did proliferate. Nuclear investment is no longer profitable, as most of the concessions that proliferation would yield have already been given up. The rising state is happy to maintain the status quo because it is already getting most what it wants. (Building would yield slightly more concessions, but it would not be worth paying the investment cost.) The rival is happy because it can keep a small amount of the concessions to itself, as the rising state is willing to accept slightly reduced offers due to the aforementioned cost savings.

The only obstacle is if the costs of proliferation are very small. Here, the rival cannot scale back very much on the deal, so the value of a nonproliferation agreement is smaller for that rival. In turn, the rival may prefer impatiently hording as much of the bargaining good as possible for as long as possible, forcing the rising state to proliferate. At that point, the rival makes great concessions.

Note that the key comparative static determining whether proliferation occurs is the cost of weapons. If the cost is high, proliferation agreements work. If not, proliferation occurs. Fortunately, nuclear weapons (and their necessary delivery systems) are incredibly expensive. Consequently, nonproliferation prevails most of the time.

However, nuclear “prestige” seems like a hindrance to the nonproliferation regime. Advocates of this theory claim that nuclear weapons bestow international prestige on their possessors, separating the owners from everyone else above and beyond the power nuclear weapons provide. There are many reasons to doubt whether such prestige actually exists–I can’t remember the last time one country was excited to hear that another one was proliferating–but let’s go with it for a moment. It then seems like prestige might sabotage those nonproliferation agreements, as it reduces the perceived investment cost for the rising state.

This has been in the back of my mind for a year or two now, and I have wondered what it meant for the robustness of my dissertation’s nonproliferation argument. Luckily, I had a mental breakthrough a couple of nights ago. The prestige argument is mostly harmless.

The key here is that prestige is zero sum. If nuclear weapons are prestigious, then no country is prestigious if all countries have them. As a result, it is incorrect to think of prestige as affecting a rising state’s perception of the cost of proliferation. Rather, prestige matters for determining the amount of goodies the rising state will receive in the future. Additional prestige means the rising state will receive more, whereas the relatively less prestigious countries (compared to today’s status quo) will receive less.

But this is just a complicated way of saying that nuclear weapons give their possessors additional concessions. Consequently, those who would have to give up the concessions should proliferation occur have incentive to reach nonproliferation agreements for the reasons outlined above. In turn, prestige has little affect on the viability nonproliferation agreements.

Nevertheless, this logic explains the competing beliefs about the existence of prestige. Rising states claim that prestige exists–because, if it does, rivals will have to give them more to reach nonproliferation settlements. Their rivals claim that prestige does not exist–because, if it does not, the cost of reaching a nonproliferation agreement will be lower for them.

If you’d like to see the argument in action, take a look at the chapter. The prestige argument is the first robustness check I run.