To limit—or expand—missile defense

Fortunately, only limited empirical evidence is available regarding nuclear weapons' effectiveness as instruments of foreign policy. This means that assessments of nuclear policy are grounded deeply in theory—and that one's views on missile defense are heavily influenced by theoretical assumptions.

But views on missile defense also depend on personal allegiances. I am a native of Romania, a second-tier US ally in Europe, so I will tend to support viewpoints that align with the interests of Romania and similar nations. I will judge theoretical approaches to missile defense in light of their implications for my own country. I believe debates over nuclear weapons and missile defense can best be understood within frameworks that emphasize disarmament, stability, or national supremacy. Which aligns best with my own allegiances?

The disarmers. Advocates for disarmament come in at least two varieties—those who reject nuclear weapons' ability to deter and constrain, and those who accept it. People in the first camp dismiss the idea that nuclear weapons can allow cooler heads to prevail. They believe instead that nuclear weapons are bound to cause miscalculation and war. Though missile defenses could potentially be used to enforce compliance in a denuclearized world, people in this first camp believe that missile defenses only distract from abolition efforts and render an already unstable world even more dangerous.

The second camp accepts the idea that nuclear weapons perform a restraining function, but believes that this benefit is outweighed by associated risks like accidental use or nuclear security hazards. Most who hold this viewpoint, though they might once have hoped to reform the current global security architecture in order to enable disarmament, have abandoned this ambition. They now hope that nuclear-armed states will recognize the risks inherent in weapons possession and proceed toward abolition. In such a scenario, conscientious governments might cooperate to establish a global missile defense system that would make nuclear-armed missiles obsolete. Thus the last nuclear holdouts could be persuaded to disarm.

At first glance, disarmers' arguments are appealing. Any use of nuclear weapons would surely have catastrophic consequences for the whole world. But with much of the planet relying on nuclear weapons for security in one way or another—and with no serious discussions under way to reform the current global security architecture—abolition remains little more than pie in the sky, no matter how desirable a goal it might be. So missile defenses must be assessed within the competitive international system that currently exists, not within a hypothetical world of enlightened governments. There is little reason to believe that any state would give up its hard-won advantages in missile defense technology or acquiesce to a truly cooperative system.

Stability seekers. The theoretical approach of stabilizers, meanwhile, is characterized by valuing the status quo and seeking to maintain it in perpetuity. Stabilizers abhor interstate conflict. They contend that in a nuclear-armed world, it is more imperative than ever that all nations employ military force only to ensure their physical security from foreign aggression. Stabilizers aim to prevent security dilemmas and thereby help avert wars. Some stabilizers would welcome nuclear abolition but assess the current prospects for disarmament as gloomy—they hope a step-by-step process will produce the desired result. Other stabilizers accept the notion that nuclear weapons are generally stabilizing, and they are willing to live with the weapons' inherent risks. But all stabilizers disapprove of challenges to the current international order.

According to stabilizers, missile defenses are both pointless and perilous. They are pointless because the overwhelming conventional and nuclear capabilities of the dominant states can deter proliferators from adventurism. Though emerging nuclear powers can inoculate themselves from invasion, they cannot coerce others into submission; they know that launching a nuclear attack would invite overwhelming punitive action. Missile defenses are perilous, meanwhile, because they can destabilize relations among great powers. If a nuclear power fears that most of its missiles could be destroyed in a first strike and the remainder intercepted by missile defenses, it will build a larger arsenal and develop its own defensive capabilities.

Stabilizers'arguments seem very reasonable from the perspective of second-tier US allies in Europe. These countries have benefitted from an unassailable US security umbrella. The resulting peace and predictability have allowed economic growth and relative prosperity. The adventurism of new nuclear powers far from European shores seems a manageable problem to nations such as Romania. It is conflict between great powers that seems threatening to them. Admittedly, some of the tension between the United States and Russia concerns missile defense. But missile defense may be only a symptom of larger disagreements between the two nations. If that's the case, banning missile defense would achieve little. US-Russia tensions would simply erupt in some other arena.

Supreme interests. Supremacists, on the other hand, are focused on furthering the well-being of their own nations by all means available. They see the world as something to be made secure for the pursuit of their interests. Stability is valuable if the status quo happens to be favorable—but if it is not, circumstances can be adjusted through the exercise of power. Though the toolbox of power contains many instruments, the ability to menace others is paramount. Tinkering with military power in a nuclear environment is surely dangerous, and an escalatory spiral is always a possibility. Supremacists, however, are comfortable leaving something to chance.

To supremacists, missile defenses are therefore useful. To be sure, stronger states can usually deter weaker nuclear states from reckless behavior. But if the preferences of dominant states collide with the fundamental interests of weaker ones, the result is an imbalance in stakes that might prevent the powerful from strong-arming the weak. A reasonably well-functioning missile defense system could provide the antidote to this problem. It would render uncertain the weaker state's ability to strike the stronger one and—along with the stronger state's ability to inflict colossal punishment—would strengthen the coercive hand of the mighty. Though missile defense might distress other great powers, it can also force them to divert scarce resources to safeguarding their nuclear deterrents. This will weaken their power in other areas.

Supremacists' arguments seem unworthy of support (except perhaps for citizens of supremacist countries). Still, from a Romanian perspective, the current US-dominated international order is very positive. However, it seems a daring bet to assume that the current international order—so favorable for my own interests—can be maintained in perpetuity without conflict. A global economic realignment is under way, and rising powers will soon demand their place in the sun. What is the best way to ensure that any transformation away from the current order is slow and non-disruptive? Will reliance on military prowess enable such a transformation, or will it only lead to war and destruction? This is a crucial question.

The current missile defense deployments of the United States are limited and toothless. Yet they serve the interests of US allies well. They represent an American trip wire, one that reassures elites in many countries that Washington is guarding their security. Whether the deployment of full-fledged defenses would further or harm the interests of US allies remains hard to tell. Then again, considering the poor performance of US missile defense in many recent tests, such full-fledged defenses might never become reality.

Should arms control arrangements include limits on missile defense? They used to—under the 1972 Anti-Ballistic Missile Treaty. The treaty included limits only on strategic ballistic missile defense, not on regional or theater ballistic missile defense, but nonetheless it contributed to strategic stability. When the United States withdrew from the treaty in 2002, and began in 2004 to deploy missile defense capabilities that would not have been permitted before withdrawal, chances increased that a new nuclear arms race would emerge.

Since the termination of the treaty, Russia has embarked on a deep modernization of its own A-135 system for ballistic missile defense, presumably with a view to giving it a more layered structure. But Russia’s system is operational only around Moscow, and though it is capable of intercepting single or perhaps multiple ballistic missiles, it would be rather ineffective against a massive missile attack. Russia, unlike the United States, has no plans to extend its ballistic missile defense system worldwide.

The United States has already begun to deploy basic elements of what might become a global missile defense system. These include a variety of means for intercepting intercontinental ballistic missiles, submarine-launched ballistic missiles, and long-range air-launched cruise missiles—as well as medium- and short-range ballistic missiles. The US system’s capabilities are still limited. But if the number of interceptors were increased, and their performance were enhanced, significant challenges would be posed for international stability and security.

Regional powers, notably Russia and China, are deeply concerned by US plans to deploy elements of missile defense systems in locations around the world. For instance, George W. Bush’s plans to create a "third site" in Poland and the Czech Republic threatened to create a crisis in US-Russia relations. The crisis was averted only when the Obama administration abandoned Bush’s plans in 2009, opting instead to pursue a "phased adaptive approach"—basically, countering known missile threats through existing means while also pursuing new technologies to counter threats that might develop in the future. Still, Moscow believes that Europe-based elements of the US missile defense system are directed against Russia, even if Washington denies it. Russia’s concerns have not been alleviated by recent reports that some NATO countries are calling for the European missile defense system to be formally directed against Moscow.

It appears that the United States may also establish a regional missile defense system in Asia—an Asia-Pacific Phased Adaptive Approach—which would entail cooperation from Japan, South Korea, and other countries in the region. It would be a layered system whose first tier would include offshore combat ships armed to intercept ballistic missiles at the boost stage, or early in the midcourse of their flight trajectories. Ground-based systems would provide a second tier. Officially, such a system would protect US and allied troops and military facilities in the Asia-Pacific region from ballistic missiles launched by states such as North Korea. But China views such plans with concern, and it would be no surprise if Beijing took countermeasures against the deployment of such a system. The region’s strategic balance would be upset under such a scenario, efforts to achieve arms reductions would be hindered, and an arms race would become more likely.

But the greatest threat associated with US ballistic missile defense would be posed by the deployment of space-based capabilities. If Washington makes a political decision to deploy space-based weapons to intercept ballistic missiles, the militarization of outer space would become inevitable. The international community would be forced to stop complying with the Outer Space Treaty. The resulting arms race in space would have unpredictable consequences and would undermine the foundations of strategic stability.

Few alternatives. Given all this, it is essential that limits be placed on ballistic missile defense within the framework of the international arms control regime. What alternatives to such an approach exist? Only two. First, missile defense could be transformed into a cooperative undertaking­—something that Russia has proposed to the United States repeatedly, but to no avail. Second, nuclear powers could engage in a renewed arms race. Russian experts are already arguing that, in response to the US deployment of a global missile defense system, Moscow should withdraw from the Intermediate-Range Nuclear Forces Treaty and resume production of intermediate and short-range ballistic and cruise missiles. (The US government, meanwhile, argues that Russia has already violated that treaty.)

Preventing the proliferation of nuclear weapons is among the top priorities on the international security agenda. It is high on the agendas of many individual countries as well. But enforcing the international nonproliferation regime will be difficult if the unrestricted development of missile defense systems leads nuclear weapon states to engage in a renewed arms race of their own. A first practical step toward averting this outcome would be to address missile defense in the next stage of US-Russia arms control negotiations.

Analysts have been discussing missile defense and its potential impact on strategic stability since the 1960s, and a basic insight that emerged decades ago still pertains today. If a nuclear-armed nation can develop a missile defense system capable of neutralizing a second nation's capacity for nuclear retaliation, the first nation's incentives for launching an initial strike will increase.

This would undermine strategic stability—so nuclear-armed states must refrain from building missile defense systems that cover their entire territories and populations. Indeed, the 1972 Anti-Ballistic Missile Treaty (ABM Treaty), a cornerstone of arms control during the Cold War, prohibited the deployment of antiballistic missile systems except around national capitals and around silo launchers for intercontinental ballistic missiles. Unfortunately, the United States withdrew from the ABM Treaty in 2002 and began to deploy a ballistic missile defense system in 2004. This has prompted serious concerns in China and Russia.

The concern springs not so much from the current US architecture for ballistic missile defense, which is small in scale and not very effective, but rather from what US missile defense might become. Today, the United States maintains 30 ground-based interceptor missiles in Alaska and California. This number is slated to increase to 44 by 2017, but even a system of that size will be incapable of neutralizing a Russian retaliatory attack. It will also be incapable of neutralizing China's nuclear deterrent. But that might change if the system displayed greater effectiveness—something the United States is working hard to achieve.

Discriminating between real warheads and decoys is the greatest challenge facing systems for midcourse missile defense. To address this challenge, the United States is deploying X-band radar in Japan and possibly in South Korea. It is constructing a new land-based X-band radar. It is developing a new "kill vehicle"—the segment of an interceptor that actually destroys a missile—that will be capable of transmitting photographs. This will help the United States implement a firing doctrine, known as shoot-look-shoot, which involves firing an interceptor, waiting to see if it has destroyed its target, and firing again if necessary. If the United States can improve its discrimination capabilities sufficiently through measures such as these, neutralizing China and Russia's nuclear deterrents will simply be a matter of deploying enough interceptors.

The United States maintains that its homeland ballistic missile defense system is intended only to guard against threats from North Korea and Iran, not from China or Russia. But if the system's purpose is really so limited, Washington should accept limits on its missile defenses. It refuses to do so. Russia has requested that the United States provide legal guarantees that its interceptors will not target Russia's strategic missiles. It has requested military-technical guarantees that a European-based missile defense system cannot neutralize Russia's strategic missiles. It has suggested that a system be established allowing NATO and Russia to exercise joint control over the launch of interceptors. The United States has resisted all these proposals, and it seems unlikely that Russia and the United States will reach a deal on missile defense in the near future. To Russia—and to China, for that matter—Washington's refusal to accept limits on its missile defense suggests that the system holds underlying potential to neutralize Russia and China's nuclear deterrents. It also suggests that the Obama administration wants to provide future administrations with the flexibility to harness this potential.

Contradictory policy. An open-ended US commitment to ballistic missile defense will hinder the global disarmament process and perhaps even trigger a renewed nuclear arms race. In particular it will be very difficult to persuade Russia, as long as the future of missile defense remains unpredictable, that strategic stability can be maintained with nuclear arsenals reduced to low levels. Moscow is already skeptical about nuclear reductions because of the US capability to launch precision conventional strikes, as well as Washington's commitment to qualitatively enhancing its offensive nuclear forces even as it quantitatively shrinks its arsenal.

From China's perspective, things look even worse. China's modest nuclear arsenal could be neutralized even by a small-scale US ballistic missile defense system—as long as the system were sufficiently effective. If China's leaders come to believe that the US missile defense system can neutralize Beijing's deterrent, they may well decide to construct more nuclear weapons to restore strategic stability. The result would be a defense-offense arms race.

The Obama administration is pursuing a contradictory nuclear policy. On one hand, the administration insists that it "will continue to reject any negotiated restraints on US ballistic missile defenses." On the other hand, it expresses a desire to maintain strategic stability with China and Russia, carry out further reductions in nuclear stockpiles, and work toward a world without nuclear weapons. The paradox is that Washington's refusal to accept limits on missile defense makes the administration's other goals unachievable. Maintaining strategic stability and making progress toward disarmament both require the United States to accept limits on its missile defenses—and also require it to demonstrate that its missile defenses are capable of countering threats only from North Korea and Iran—not from China and Russia.

Future arms control arrangements must include limits on missile defense. Given US concerns about missile threats from countries such as Iran and North Korea, it seems impractical simply to resuscitate the ABM Treaty and try to “uninvent” US homeland missile defense. But limits on strategic defensive capabilities must be embedded in any future agreements on strategic offensive weapons. If Russia and the United States negotiate further treaties to reduce nuclear arsenals, limits on missile defense must be an element. And if the United States expects China not to expand its nuclear arsenal, it must give China assurances that the effectiveness of its missile defense system will remain at a modest level—robust enough to counter the simple intercontinental ballistic missiles that North Korea or Iran might fire, but unable to contend with China’s sophisticated missiles. As a first step, the United States must express a political willingness to accept limits on missile defense. This is a precondition for any serious arms control dialogue going forward.