The United States and Russia possess intercontinental ballistic missiles (ICBMs), submarine launched ballistic missiles (SLBMs), and nuclear bombers. Both also possess tactical nuclear weapons. Stemming from the 1987 Intermediate-Range Nuclear Forces (INF) Treaty, though, neither nation possesses ground-launched missiles with ranges between 500 and 5500 kilometers – either conventional or nuclear-capable. China, India, Pakistan, and Iran are all developing such mid-range missiles armed with conventional weapons.

To address the missile future, Carnegie hosted Henry Sokolski, executive director of the Nonproliferation Policy Education Center, in a discussion of his recent article, “Missiles for Peace.” Sokolski argued that emerging missile threats, in conjunction with weak defenses and constraints on missile production, suggest a need to think more creatively. He outlined three strategies that could be pursued singly or in some combination: missile defense, extending the INF treaty, and pursuing a fast conventional strike capability.

Vulnerabilities and Shortcomings

Sokolski highlighted some of the chief missile challenges facing the United States:

  • Emerging missile threats: China is developing mid-range conventionally-armed missiles able to target Japan, Taiwan, India, and U.S. military bases in the South Pacific. China is also developing missiles able to hit moving targets. While the United States and Russia are constrained by the INF Treaty, China can exploit the resultant missile gap. Iran is also working on developing more advanced missiles.
  • Missile defense: Currently, no missile defenses can reliably intercept an incoming missile mid-course or target and destroy a missile immediately after it has been launched, during the boost-phase. As a result, missile defense is essentially limited to terminal interceptors, which target incoming missiles just after they reenter the atmosphere, when they have nearly reached their targets. Relying on terminal missile defense requires numerous interceptors, since these defenses must anticipate targets across the entire country rather than monitor the locations from which missiles could be launched. The United States currently has just 30 ground-based interceptors to protect all fifty states, and these have performed inconsistently in tests.
  • Vulnerable missiles: Non-mobile Minuteman III missiles are kept in silos which could be easily targeted by enemy missiles, noted Sokolski. Dismantling any of them in the context of the New START Treaty would be more costly than converting them to carry conventional weapons. If the missiles are already vulnerable, Sokolski argued, they ought to be made non-nuclear. About $900 million would be sufficient to convert 50 of the 450 U.S. Minuteman III missiles to non-nuclear payloads in eighteen months.

Potential Solutions

Sokolski asserted that developing a conventional fast-strike capability, such as Prompt Global Strike, could prove advantageous not only in countering new, advanced missiles, but also in giving the United States leverage to broker missile reductions.

  • Prompt Global Strike (PGS): PGS is a conventionally armed missile system that is still in the research and development phase. The system involves a hypersonic glider that would be launched from an ICBM, enabling the United States to launch fast strikes with conventional forces. At present, the only fast strike capabilities open to the United States are nuclear; if successful, PGS could target anywhere in the world in less than an hour. While the first test of the system failed, the Pentagon continues to be optimistic and intent on securing this capability, according to Sokolski.
  • Convert All Minuteman III Missiles: Converting all Minuteman IIIs to conventional payloads would eliminate all U.S. ground-based nuclear weapons. Sokolski argued that such a step would eliminate a vulnerable class of nuclear weapons. Furthermore, as a trust-building mechanism, the United States could invite Chinese and Russian inspectors to view the missiles. He added that converting Minuteman IIIs to carrying conventional weapons would be allowable under New START. Such conventional missiles would then no longer count toward U.S. ballistic missile limits under the treaty.
  • Targeting: The military has only spoken obliquely on PGS targeting, offering a wide range, from use in Afghanistan to use against Chinese missiles. Even if PGS could not attack mobile missiles directly, the system could target key infrastructure necessary for mobile missiles, such as bridges, rail lines, command and control systems, and storage facilities, Sokolski noted.
  • Shorter-Term Options: PGS is a distant prospect. In the shorter term, Sokolski offered three options.

    • First, the United States could mimic the Russians by threatening to withdraw from the INF Treaty. Alternatively, and more productively, the United States could work to extend the INF treaty, incorporating Iran, China, India, and Pakistan. Broadening membership in the INF treaty would avoid a missile race and better secure all participating nations.
    • Second, if inclined towards expanding conventional fast-strike capabilities, the United States can use the X-37, a robotic space plane. The X-37’s first experimental launch was successful. Also, it is considerably less costly than PGS.
    • The United States could work on improving its missile defense capabilities.

Analysts pay insufficient attention to the missile threat from China, Sokolski warned. Ballistic missile defense is not advanced enough to negate this threat. Incorporating missile proliferators into the INF treaty would counter the mid-range missile threat. Developing a fast-strike conventional capability could help address the oft-neglected missile threat and provide the United States with much-needed leverage to coerce reduced missile production by other states.   

Perkovich concluded by highlighting the contribution of Sokolski’s article to the conventional deterrence debate. Even a world without nuclear weapons, he observed, will include threats and missiles. Whether Prompt Global Strike affects the likelihood of war remains a vital question.