CHAPTER 1
The Strategic Logic of Nuclear Monopoly
The crux of the argument is that there are costs and benefits to any use of nuclear weapons. A state without nuclear weapons contemplating confronting a nuclear-armed opponent can take advantage of this situation. As long as the nonnuclear weapon state believes that it can maintain a situation in which the costs of nuclear use for its opponent outweigh the benefits, it is able to take action. The NNWS essentially sets its own “red lines” and gambles that those lines are below the red lines for nuclear use by the nuclear weapon state. In many situations the NNWS will actively seek to manipulate the red-line threshold by pursuing strategies it believes will further reduce the benefits and/or increase the costs of nuclear use. In other situations, the preferred strategy of the NNWS will already exist below the red line, and it will not need to alter its behavior. The exact mix of strategies varies across cases. All else equal, though, the more conventionally capable the NNWS is militarily relative to the NWS, the more constrained the behavior of the NNWS will be. As such, conflicts are likely to escalate to war only when the NWS possesses a large conventional military advantage.
The opponent’s nuclear arsenal is not the sole determinant of NNWS strategy or behavior. Similarly, my argument does not predict that a conventionally weak NNWS will rush into war. A state without nuclear weapons may avoid fighting because of the conventional military balance, the level of international support it enjoys, its domestic situation, cultural features, and even individual personalities. The argument is simply that the NNWS will act below the threshold it identifies, and that a conventionally powerful NNWS must behave more cautiously.
To construct this argument, I first identify the main benefits and costs of nuclear use. I initially focus solely on nuclear weapons, ignoring conventional capabilities and strategies. This provides a baseline treatment of the nuclear environment that both the NWS and the NNWS confront. Next, I use this baseline to outline NNWS strategies to reduce those benefits and/or raise the costs of nuclear use. I pay attention to both deliberate and inadvertent pathways to nuclear escalation. As long as the NNWS believes that the costs outweigh the benefits of nuclear use, it has a space to act. The third section incorporates the role that the conventional military balance plays in influencing the costs and benefits of nuclear use. Having built the argument in three stages—abstract nuclear monopoly, NNWS strategies in nuclear monopoly, and the role of the conventional military balance—I then present its main predictions. In the following section I discuss how I assess the argument. I conclude by summarizing the core claims of this chapter.
Costs and Benefits of Nuclear Use
Nuclear weapons promise nuclear-armed states various benefits in a dispute. I use the term “benefits” to refer to the military and political utility for the nuclear-armed state of a threatened or executed nuclear strike. The discussion on nuclear-weapon effects necessarily informs decision making prior to strikes because leaders can assess the likely consequences of nuclear use.1 The relative efficacy of nuclear versus conventional strikes influences the scope of the benefits. At the same time, there are costs associated with nuclear use that go beyond the typical costs associated with using force. The rest of this section outlines both elements.
BENEFITS OF NUCLEAR USE IN MONOPOLY
The core benefit of threatening or using nuclear weapons for a nuclear-armed state is to improve the likelihood of attaining a favorable settlement. The benefits of a nuclear strike depend on the conventional alternatives and the military and political situation. Failure to appreciate this point might lead one to conclude that nuclear weapons would always be used in the absence of a strong legal or normative prohibition. There is no specific benefit from a nuclear strike if the mission can be performed equally well by a conventional alternative. Any costs associated with nuclear use would then be sufficient to dissuade such a strike. Additionally, the higher the danger to the state and the worse the military situation, the greater a state benefits by using nuclear weapons to attain a favorable outcome. Inhibitions on the use of force decrease as the likelihood and consequences of defeat increase.
The NWS can threaten or execute several types of nuclear strikes. The two most basic are punishment and denial.2 In brief, punishment seeks to harm or threaten the opposing population. Depending on the situation, that hardship will cause the adversary to not undertake some action, cede to political demands, or stop fighting. The victim government may see the destruction visited on its society and accede to the desires of the NWS. Alternatively, the population may itself rise up to demand their government implement (or not implement, in the case of a deterrent threat) the policies the NWS seeks. Punishment was the primary logic behind the American decision to use nuclear weapons against Japan in 1945 in hopes of compelling Japan to surrender.3 By contrast, denial strikes target the opponent’s military capabilities to block the adversary’s ability to successfully prosecute its campaign. Denial threats seek to deter any action or compel acquiescence by convincing the opponent its military strategy will not succeed. The two categories will sometimes blur, but they are important to keep analytically distinct. In addition, nuclear-armed states may contemplate using limited strikes to de-escalate a dispute or to catalyze third-party involvement. I discuss each option in turn.
Nuclear weapons offer an effective, if gruesome, tool for punishment strikes. Most basically, nuclear weapons are very destructive.4 Accuracy is not particularly important when targeting a large urban area with a nuclear device. The overpressure generated by nuclear detonation is sufficient to destroy most civilian structures kilometers from the blast center. Individuals near the blast will also be exposed to lethal radiation. The heat from the blast, combined with high wind speeds and debris, create fire-storms that cause even greater devastation. As Lynn Eden notes, depending on the conditions, the fire could “generate ground winds of hurricane force with average air temperatures well above the boiling point of water.”5 To be sure, a low-yield fission weapon would not completely destroy a large city. Hills and other geographic features can shield people otherwise near the blast. Yet even comparatively low nuclear yields can have devastating effects. The 15-kiloton blast at Hiroshima—current US intercontinental ballistic missiles have warhead yields of 300 to 335 kilotons—created a fire that “covered an area of roughly 4.4 square miles and burned with great intensity for more than six hours after the initial explosion. Between 70,000 and 130,000 people died immediately from the combined effects of the fire, blast, and nuclear radiation.”6 Faced with the prospect of such destruction, the pressure to cede to the adversary’s political demands is intense.
Nuclear weapons are also useful at destroying vital civilian infrastructure. Dams, ports, large rail centers, and other critical components may withstand conventional attacks not powerful or accurate enough to do sufficient damage. For instance, Secretary of State Dean Rusk told President Lyndon Johnson in 1965 that Israeli officials believed that a nuclear weapon would provide Israel “a capability to bomb and release the waters behind the Aswan High Dam. Destruction of the Aswan Dam would require a nuclear warhead; bombing with high explosives could not be counted on to do the job.”7 An earlier State Department report in 1964 highlighted that “a single well-placed nuclear device would bring a sheet of water 400 feet high cascading down the narrow Nile valley where the entire Egyptian population is concentrated”8
States can carry out punishment campaigns with conventional weapons, of course. Naval blockades and scorched-earth land campaigns can devastate civilian populations. The advent of air power in the early twentieth century provided a powerful new punishment tool. For instance, on March 9, 1945, the United States launched a massive firebombing attack on Tokyo. The raid burned 15.8 square miles and killed an estimated 84,000 to 100,000 Japanese.9 Advances in precision-guided munitions can cripple infrastructure to impose suffering. During the 1991 Gulf War, precision bombing avoided directly targeting civilians but destroyed electrical and water facilities. Nina Tannewald highlights that those strikes caused “vast numbers of civilian deaths due to infectious diseases, and lack of food, water, and medical care.”10 Conventional punishment campaigns have occasionally been successful, though they often require major fighting to first degrade the adversary’s military capability and can take a long time to result in the desired effects.11 Moreover, prior to hostilities target-state leaders frequently believe they can outlast limited air strikes.12
The key distinction with nuclear weapons is economy and speed. A single weapon is enough to do what can otherwise require a large number of strikes. A state need not outfit an aerial armada and command the skies to threaten or inflict severe punishment. Developing stealth and precision-guided technology and overcoming enemy air defenses is not necessary to impose widespread hardship.13 In a conventional world, intercepting most of the adversary’s aircraft or missiles allows the population to escape destruction. In a nuclear world, intercepting most of the adversary’s aircraft or missiles still results in devastating destruction.14 Moreover, nuclear strikes can occur in a matter of minutes and in many cases are on platforms that offer coverage of the entire enemy territory. As Christine Leah puts it, “It is the sheer destructive power, and the speed at which that power can be dealt, that make nuclear armed missiles unique.”15 In a conventional situation, then, leaders may be willing to roll the dice and press ahead or not give in to demands. “Wars start more easily” in a conventional world, Kenneth Waltz argued, “because the uncertainties of their outcomes make it easier for the leaders of states to entertain illusions of victory at supportable cost.”16 By contrast, faced with the prospect of immediate nuclear devastation on at least some part of their society, those same leaders and publics are more cautious.
Nuclear denial strikes possess many of the same advantages of speed and economy. They allow an outnumbered or outgunned actor to radically increase its units’ firepower. Nuclear weapons would be particularly useful against massed enemy formations. Nuclear strikes in an operational role can interdict the adversary’s ability to bring up reinforcements and supply frontline units. During World War II, various American leaders were already speculating along these lines. In 1943 General Leslie Groves, head of the Manhattan Project, and his advisers discussed using a nuclear weapon against “a Japanese fleet concentration” in harbor.17 Following initial uses at Hiroshima and Nagasaki, Lieutenant General John Hull noted nuclear weapons might be useful at “neutralizing a division or a communication center or something so that it would facilitate the movement ashore of troops.”18 More recently, Pakistan is widely believed to have adopted a nuclear posture that envisions battlefield use of nuclear weapons against Indian conventional forces to offset Pakistani military inferiority. As Vipin Narang argues, Pakistan’s status as the “conventionally weaker power” led it to integrate nuclear weapons into its military doctrine and adopt “an asymmetric escalation posture that attempts to credibly deter conventional attack by threatening the first use of nuclear weapons against a large-scale Indian conventional thrust through Pakistan’s vulnerable desert and plains corridor in Sindh and Punjab.”19 Though in the latter example both sides possess nuclear weapons, the essential logic applies in nuclear monopoly.
States can also use nuclear weapons in a strategic denial role, such as targeting the adversary’s industrial production so that it cannot sustain its military forces. American planning against the Soviet Union in the early postwar period called for targeting industry to degrade the Soviet ability to wage war.20 Another target set is the staging areas for the adversary’s military forces. For example, conventional cratering of runways may not do sufficient damage over large enough areas to make the runways inoperable. Nuclear strikes, by contrast, are more likely to successfully destroy runways and can be used against hardened aircraft shelters.21
Nuclear weapons are especially valuable in destroying hardened and buried targets.22 This is particularly true if weapon accuracy is limited. In those cases, larger yields compensate for reduced accuracy. Strategic studies tend to focus on targeting an adversary’s hardened nuclear forces.23 In nuclear monopoly, the NNWS possesses no nuclear assets to attack. Yet conventional missiles, aircraft shelters, artillery units, communications and command centers, and other military targets that the adversary may harden, bury, or dig into mountains still pose difficulties for conventional weapons.24 For instance, experts debated whether even the most powerful US conventional weapons could destroy the deeply buried Iranian nuclear facility at Fordow.25 Particularly when speed is critical, nuclear weapons may offer an attractive alternative against such targets.
The increased destructive power and speed of nuclear-armed missiles offer advantages against mobile targets relative to conventional alternatives. During the 1991 Gulf War, the United States tasked approximately one thousand “Scud-patrol” sorties alongside fifteen hundred strikes against Iraqi ballistic-missile capabilities. There were no confirmed destructions of Iraqi Scud missiles.26 As Charles L. Glaser and Steve Fetter note, though, “On many occasions U.S. forces located Scud launchers in Iraq, but without enough precision to allow a successful attack with the conventional weapons available. Nuclear weapons have a much larger radius of destruction against mobile missiles, which would make relatively unimportant any lack of precision.”27 Similarly, Austin Long and Brendan Green argue that “uncertainty about target location matters much less when using fast nuclear weapons rather than much slower fighter-bombers armed with conventional weapons.”28
Limited nuclear use against a military target or isolated area may have little immediate effect but instead serve as a warning. In this sort of “escalate to de-escalate” scenario, the nuclear state derives benefit by signaling to the NNWS a willingness to use nuclear force. Such a signal conveys that now that the nuclear threshold has been breached, any additional action can result in more substantial denial or punishment strikes. As Caitlin Talmadge writes, “Nothing says ‘you’ve crossed my red line’ quite like a mushroom cloud.”29 Because this ultimately rests on the threat of additional denial or punishment strikes, it can be folded into the general denial and punishment discussion above.30
Nuclear-armed states might also believe that nuclear weapons can provide a catalytic benefit. In this scenario, the NWS threatens to or actually detonates a device, likely in a remote area, to spur third-party involvement.31 The third party can support the NWS through direct engagement, furnishing of supplies, or pressuring the NNWS. There is some evidence that Israeli leaders performed various operational checks on their nuclear arsenal in the 1973 October War to spur greater US involvement.32
This is unlikely...
