战略军备控制的未来.docx

CONTENTS1 Introduction3 The Benefits of Arms Control7 The Challenges to Arms Control15 The Scope for Arms Control21 Progress: The Way Forward for U.S. Policy27 EndnotesAcknowledgments35 About the Authorprofound difference between U.S., Chinese, and Russian nuclear postures and strategies-all of which exist within a multipolar nuclear order that also includes states such as India, North Korea, and Pakistan.China will be the United States' chief rival over the coming decades, but that competition is exceedingly unlikely to play out in the domain of strategic nuclear weapons. Whereas the nuclear arms race was a central feature of bipolar U.S.-Soviet rivalry during the Cold War, China has never ascribed the same military or diplomatic significance to nuclear weapons.17 With approximately 320 weapons, China's nuclear arsenal is roughly equivalent in size to France's and represents about 5 percent of the United States5 and Russia's respective arsenals. China also has a long-standing declaratory policy of nuclear “no first use.，M8China, however, is in the midst of a military modernization program that will likely change the nuclear balance between the United States and China, even if it remains far from parity. The Pentagon estimates China's nuclear arsenal will double over the next decade, suggesting China could become a nuclear triad power.19 Beyond nuclear weapons and delivery systems, China is pursuing new asymmetric counterspace and cyber capabilities.20 The considerable secrecy surrounding these developments, as well as the emphasis on rising Chinese military power and growing geopolitical ambitions in the few publicly available doctrinal documents, has increased U.S. alarm about expanding capabilities and hostile intentions.21 Even with these changes, however, the United States would retain a sizeable quantitative and qualitative overmatch.Yet if U.S.-Russia arms control were to proceed along its current path, these China-centric risks would go unaddressed一and, in some cases, a purely bilateral framework could expose both the United States and Russia to new dangers generated by China's unconstrained military modernization.22 Given the warming relationship between China and Russia, Russia could possibly be more tolerant of changes to the trilateral strategic balance-though, with a shared border, overlapping notional spheres of influence, and a history of cooperation-turned- enmity, Russia has reason to be warier of growing Chinese military power than it publicly acknowledges.23 The United States is of course in a different position. Sino-U.S. relations are on a downward trajectory, which COVID-19 has only accelerated, and the two nations have sharply different visions for the future of the Asian regional order.24 The United States can only deter a Chinese bid for regional hegemony and preserve its position as an Indo-Pacific power if it maintains a military presence sufficient to ensure the costs of any U.S.-China war remain prohibitively high.25Russia and its nuclear forces present a distinct challenge. Although the Trump administration National Security Strategy and National Defense Strategy grouped China and Russia together, Russia's economy is far smaller than China's and it has no prospects of becoming a global system leader. Russia is, however, revanchist in its ambitions to establish a sphere of influence in its near abroad, capable of acting as a regional or global spoiler, and enduringly proficient in the nuclear domain.26 Indeed, Russia has the world's largest nuclear arsenal and, as two scholars observe, “Russia's leaders see nuclear weapons much as their Soviet predecessors did: as guarantors of peace and security among great powers” and also as tools of political power and influence.27 Russian revanchism has intersected with its military modernization, resulting in a more assertive foreign policy that elevates nuclear weapons as a coercive tool in times of peace, crisis, and war.28 The deployment of intermediate-range missiles in violation of Russia's Intermediate-Range Nuclear Forces (INF) Treaty commitments exemplifies the tension between Russia's apparent strategy and its commitment to a robust arms control regime.Although New START places verifiable limits on Russia's deployed strategic nuclear forces, it does not address the full range of Russian nuclear capabilities. Russia retains a sizable arsenal of nonstrategic (short range or “tactical")nuclear weapons, which are more usable for warfighting, including as part of a possible "escalate to deescalate” strategy that seeks to blackmail the United States or the North Atlantic Treaty Organization (NATO) into tolerating a Russian fait accompli by credibly threatening unacceptable nuclear escalation. The collapse of the INF Treaty repealed limits on Russia's intermediate-range nuclear forces. Russia is also undertaking a modernization program that will yield a variety of exotic new systems. Some are strategic systems that would count under New START limits (such as the Avangard hypersonic glide vehicle, or HGV, and Sarmat heavy ballistic missile) and others are potentially destabilizing new capabilities that fall outside of the treaty (such as the Poseidon underwater drone, the Burevestnik nuclear-powered cruise missile, the Kinzhal air-launched ballistic missile, and the Tsirkon hypersonic cruise missile).29In light of these triangular asymmetries, arms control that is comprehensive, symmetrical, and bindingthat is, arms control that replicates the U.S.-Russia model in trilateral form一will be impossible to achieve. Whereas a mutual and formal recognition of mutually assured destruction served as the basis for U.S.-Russia arms control at a time when those states had fairly symmetrical nuclear arsenals and doctrines, no corresponding recognition exists between the United States and China or China and Russia. Given these differences, the U.S.-Soviet approach for arms control and nuclear risk reduction is unlikely to succeed for the United States and China.30 Nevertheless, trilateral negotiations could prove fruitful in generating reciprocal restraints of a different, and initially more modest, variety. Such negotiations could also serve a broader, strategic end: creating friction and exposing divergent interests between China and Russia at a time when they are increasingly aligned in opposition to the United States.31EMERGING TECHNOLOGIESThe confluence of progressive military modernization and technological innovation risks a new age of strategic instability. Cyber, AI, hypersonics, and space-based capabilities can upend crisis stability, as cross-domain escalation dynamics remain poorly understood.32 Technological breakthroughs also raise the possibility of real or perceived first-strike incentives一particularly when they result in novel vulnerabilities that adversaries can exploit.33 Given this complexity, a strategic arms control regime that focuses exclusively on nuclear forces will prove progressively less stabilizing over time, as technology continues to evolve.A range of emerging technologies has the potential to undermine strategic stability. Cyber is perhaps the most pressing concern. Militaries5 increasing reliance on digital information systems, including for command and control, creates new forms of vulnerability, as perfectly impenetrable cyber defenses are impossible to erect.34 This apparent vulnerability, in turn, could undermine command and control system survivability and, when combined with the threat of conventional and nuclear counterforce strikes, magnify instability. Inadvertent escalation is a further risk. As cybersecurity and AI scholar Ben Buchanan and political scientist Fiona Cunningham point out, distinguishing between hacking for espionage and preparation of the environment as a precursor to a cyberattack is exceedingly difficult.35 Combined with "use it or lose il” pressures, misperceived espionage could represent an additional route to nuclear escalation. Beyond cyber vulnerabilities, the introduction of novel cyber capabilities could also be destabilizing if they enable existing weapons systems to perform faster, more accurately, or with greater stealthan outcome made more likely by advances in artificial intelligence.36 Although cyber and AI implicate nuclear stability, they defy traditional models of arms control because they are “invisible” capabilities, prone to rapid change and improvement, and especially secretive because disclosure can obviate a military advantage.37Space systems are not new, but their increasing sophistication and integration into command and control amplifies destabilizing risk. The United States, China, and Russia all operate satellites for espionage purposes, and the ability to capture frequent, high-resolution images is progressing rapidly. Particularly when combined with other forms of sensing and AI, these advances in space-based surveillance could provide real-time tracking for mobile missiles. Such intelligence advances would enhance counterforce targeting, potentially calling into question China or Russia's second-strike capabilities.38The United States also relies on satellites for its early warning and command and control systems, making it vulnerable to anti-satellite attacks, and China and Russia likely do the same.39 Yet most satellites have no defensive capabilities other than the ability to maneuver out of the way of an approaching object. They also lack onboard sensors to detect approaching objects and require human intervention to respond or move out of their programmed orbit.40 This vulnerability creates the risk of attacks on early warning satellites. Because these satellites warn early of both nuclear and conventional attacks, an effort to disable them as part of a conventional attack could be interpreted as an attempt to blind U.S. early warning against a strategic nuclear attack.41 Chinese and Russian development of anti-satellite weapons suggests such an attack is a real possibility. Moreover, given the difficulty of defending satellites against attack, even the fear of an attack on satellites necessary for command and control could generate first-mover pressures to attack another country's satellites.42 Arms control for space-based assets and operations could be possible, as satellite numbers and orbits are relatively straightforward to verify and new launches are readily observable.43 Yet any progress toward arms control in space could require parties to sacrifice perceived advantages一including in the conventional domain一which could prove prohibitive, especially given sharper geopolitical rivalry.Maneuvering hypersonic glide vehicles are a third type of emerging technology that could prove destabilizing-though they could also prove amenable to integration within existing arms control regimes. Maneuvering hypersonic glide vehicles are missiles that can be launched into the atmosphere like intercontinental ballistic missiles (ICBMs) but that have greater maneuverability upon reentry, so as to take an unpredictable path and evade defenses en route to a target. In addition to their intercontinental range, they are extremely fast, with speeds greater than Mach 5 (i.e., five times the speed of sound), and support heavy pay loads. Although the United States does not plan to place nuclear warheads on hypersonic glide vehicles, China and Russia are developing hypersonic weapons that could be tipped with nuclear warheads.44 Hypersonics risk escalation through their extreme speed and potential for nuclear-conventional entanglement. As command and control for nuclear and nonnuclear systems are increasingly entangled, the speed at which hypersonic vehicles operate heightens the risk of misinterpreting a conventional strike as a nuclear one, especially with diminished decision time.45 Even so, the apparent novelty of hypersonics remains questionable: a ballistic missile submarine launch could result in similarly foreshortened decision time, existing nuclear delivery systems have the ability to carry conventional payloads, and Russia's hypersonic boost glide missile was already classified as an ICBM under New START limits.46 This precedent could make it easier to classify other hypersonic weapons as ICBMs and fit them into existing, understood procedures for delivery vehicle limits. The relatively slower pace of technology development in hypersonic weapons, in contrast to other emerging technologies, could also make arms control more feasible.47The destabilizing effects of many emerging technologies remain largely prospective, as much will depend on these capabilities5 development trajectories and how militaries ultimately adopt them.48 For all the difficulties of regulating emerging technologies一and doing so in a verifiable manner-their effect on strategic stability could hold promise for future arms control regimes that exert stabilizing influence on the employment of new technologies, even if the technologies themselves cannot be proscribed. Furthermore, technological innovation could yield breakthroughs in states' ability to conduct verification, monitoring, and intelligence collection. The latter could be particularly important for informal agreements that rely on unilateral monitoring via national technical means (NTM).49U.S. DOMESTIC POLITICSAn inhospitable domestic-political environment within the United States compounds the international hurdles to arms control. All of the U.S.- Russian arms control treaties that entered into force during the Cold War received bipartisan approval with eighty-eight or more affirmative votes. By contrast, the most recent bilateral arms control agreement一 New START, ratified in 2011passed seventy-one to twenty-six, with only 32 percent of Republican senators supporting the treaty.50 This outcome seems to reflect several trends and dynamics in U.S. politics that portend greater difficulty for future arms control treaties.The first trend is sharpening partisan polarization in the United States-not only among the mass public, but also evident among policy elites-as Democrats and Republicans have sorted into two opposing political camps.51 Partisan polarization hampers U.S. foreign policy in many respects, including by presenting barriers to treaty ratification, which requires a two-thirds vote by the U.S. Senate. Over the last two decades, the number of new international agreements concluded by the United States has plummeted. Treaty ratification has experienced an especially sharp downward turn.52 Although not solely attributable to partisan polarization, this trend does reflect fundamental divergence on the nature of U.S. interests and the best methods to achieve national security objectives, especially as concerns about the encroachments of international law on U.S. sovereignty have become a particular stalking horse of some on the ideological right.53 Diminished cong