It is a supreme irony that even if the spread of missile technology can be constrained, proliferation of missiles will likely remain unconstrained. Today, more than 30 countries possess missiles with ranges of 150 kilometers or greater. In 2016 alone, nations including China, India, Iran, Israel, North Korea, Pakistan, Russia, and the United States have conducted a spate of missiles tests meant either to develop new missiles or improve existing ones. Most if not all of these tests have showcased missiles based primarily on indigenous technology—underlining the reality that technology denial alone will not prevent missile development.
A few factors help explain these proliferation trends. First, in the words of a UN panel of government experts, "there is still no universal norm, treaty, or agreement governing the development, testing, production, acquisition, possession, transfer, deployment, or use of missiles." To be sure, concern over missiles is a matter of broad consensus, particularly for missiles capable of carrying nuclear weapons and other weapons of mass destruction. But little agreement exists about how to address the WMD missile challenge. At best, the UN Security Council has produced country-specific resolutions regarding instances of missile proliferation that threaten international peace and security, for example where Iran and North Korea are concerned.
Second, a general diffusion of information and technology from the original suppliers means that almost any country that decides to acquire WMD-capable missiles will, regardless of its economic strength and technological capability, manage to do so—despite the best efforts of the international community. Sanctions, or constraints on technology transfers, might slow a missile program. But they are unlikely to stop it if the country is determined.
Third, even if the majority of proliferating countries must beg, borrow, or steal technology and materials in the initial stages of their WMD-capable missile programs, they will eventually establish indigenous capabilities—thus insulating themselves against sanction regimes that seek to block the export of weapon-related dual-use technology.
Two paths. Missile proliferation is difficult to address partly because proliferators, motivations and capabilities for proliferation, and missiles themselves are all quite diverse. Today's missiles vary from man-portable, shoulder-fired, anti-armor missiles with ranges in the hundreds of meters—to missiles weighing some 100,000 kilograms at launch, capable of carrying multiple nuclear warheads, and with ranges exceeding 10,000 kilometers. Almost all nations possess missiles, though their holdings vary considerably in quantitative and qualitative terms. In recent years, even terrorist groups and armed non-state actors have acquired and used man-portable missiles with ranges under 150 kilometers, allowing them to threaten targets such as civilian aircraft.
Against this backdrop, two general approaches to missile proliferation have emerged. The approaches are not mutually exclusive and indeed often overlap. The first is a series of political and diplomatic initiatives at the bilateral, regional, and global levels, including the Intermediate-Range Nuclear Forces (INF) Treaty, the Missile Technology Control Regime, the Hague Code of Conduct Against Ballistic Missile Proliferation, and three successive UN panels of government experts.
The INF Treaty, signed by the United States and the Soviet Union in 1987, successfully eliminated ground-launched ballistic and cruise missiles with ranges between 500 and 5,500 kilometers. But the treaty is now in danger of unraveling as Moscow threatens to withdraw from it, partly because of Washington's withdrawal from the 1972 Anti-Ballistic Missile Treaty. The Missile Technology Control Regime has had its own limitations. The regime, established in 1987 primarily to curtail the spread of missiles capable of delivering nuclear weapons, has failed to garner universal appeal because of two key shortcomings. First, its scope was initially restricted to ballistic missiles (and, later, other unmanned delivery systems) capable of delivering WMD or carrying a 500-kilogram payload a distance of 300 kilometers. Conventionally armed cruise missiles were ignored. Second, the regime focuses on horizontal proliferation (the spread of missiles to newer states) rather than on vertical proliferation (qualitative and quantitative improvements in missiles by existing missile-possessing states).
Regime members, partly in response to the regime's shortcomings, initiated the Hague Code of Conduct, which came into effect in 2002. Unlike the regime, the code does not seek to prevent states from acquiring or possessing WMD-capable ballistic missiles. It merely seeks to promote responsible behavior, through confidence-building and transparency measures, regarding ballistic missiles (though not cruise missiles). While 138 nations have signed on to the code, several key states that possess WMD-capable missiles have not done so—among them China, North Korea, Iran, Israel, and Pakistan.
The second primary approach to missile proliferation involves military and technological initiatives—such as the 2003 invasion of Iraq (intended in part to destroy Iraq's nuclear and missile programs) and the development of missile defenses.
The Iraq invasion, of course, was meant not just to disarm Iraq but to dissuade other nations, particularly Iran and North Korea, from pursuing missile and nuclear capabilities. But Iran, far from abandoning its contentious programs, embarked on an effort to build missiles capable of delivering a one–metric ton warhead more than 2,000 kilometers away. North Korea, meanwhile, began a series of WMD-capable missile tests that has continued despite increasingly severe international sanctions. The unintended consequences of the 2003 Iraq War, still reverberating more than a decade later, make it highly unlikely that such an approach will be repeated in the near future.
Missile defense programs, meanwhile—which seek to develop the capacity to detect, intercept, and destroy ballistic missiles before they strike their targets—are maturing at a rapid pace and now threaten to undermine strategic stability among the United States, Russia, and China. The latter two countries have embarked on their own missile defense projects, even as they object to the US program. Additional nations, including India, Israel, Japan, and South Korea, will likely deploy or improve missile defense systems in the foreseeable future as a response to missile proliferation. While the effectiveness of these systems remains unproven in many cases, they are sometimes perceived as a partial panacea for the missile threat.
Political and diplomatic initiatives against missile proliferation have been somewhat limited in their effectiveness; the same can be said of military action and missile defense. Yet both approaches are likely to persist. Political and diplomatic initiatives remain crucial to building the norms and instruments that might constrain proliferation, and are also key to encouraging responsible behavior among states that already possess strategic missiles. And the chance remains that these initiatives might one day gain universal adherence.
Military action and missile defense will likely have limited appeal going forward—especially the latter, which is available only to nations that can develop missile defense capabilities on their own or gain protection from another country that possesses such capabilities. But even if missile defense represents a way to respond to missile proliferation, it isn't likely to curb proliferation. To the contrary, all indications are that missile defense will produce yet more vertical missile proliferation—as nations try to defeat missile defense systems with overwhelming numbers of missiles or other countermeasures.