Conventional Warheads for Long-Range Ballistic Missiles: Background and Issues for Congress

Publication Date: January 2009

Publisher: Library of Congress. Congressional Research Service

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Research Area: Military and defense

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Abstract:

The United States has deployed long-range ballistic missiles in its strategic offensive nuclear forces for more than 40 years. Recently, some have proposed that the United States deploy conventional warheads on these missiles. This would provide the United States with the ability to strike promptly anywhere in the world, regardless of the presence of overseas bases or nearby naval forces.

The Air Force and Navy have both studied the possible deployment of conventional warheads on their long-range ballistic missiles. The Navy sought funding, in FY2003 and FY2004, for research into a reentry vehicle that would be able to maneuver when approaching its target. The FY2007 Defense Budget requested $127 million to pursue the deployment of conventional warheads on Trident missiles, but the 109th Congress rejected most of this request; the FY2008 budget requests $162.4 million. The Air Force is pursuing, with DARPA, research into a number of technologies that might enhance the U.S. long-range strike capability. In particular, it is developing a hypersonic glide vehicle, known as the Common Aero Vehicle (CAV), that could carry conventional munitions on modified Minuteman II or Peacekeeper missiles, or it could deploy these missiles with more familiar conventional warheads. This effort, now known as the Conventional Strike Missile (CSM), could serve as a follow-on to the conventional Trident modification. The 110th Congress is likely to review these programs again when addressing the FY2008 budget request.

Many have expressed concerns about the possibility that other nations, such as Russia or China might misinterpret the launch of a conventionally-armed ballistic missile and conclude that they are under attack with nuclear weapons. The Air Force has outlined a number of measures that might reduce this risk. It plans to base these missiles along the U.S. coast, far from bases with nuclear-armed ballistic missiles. It also would use consultations, notifications, and inspections to inform others of the difference between conventional and nuclear ballistic missiles. But, although these measures could address some of the concerns, they are not likely to eliminate the risks of misunderstandings, particularly if the United States used these missiles on short notice in a crisis. The Navy would not segregate its conventional missiles, but would deploy them on submarines that also carry nuclear warheads, but it could still notify Russia or other nations to mitigate the possibility of misunderstandings.

Long-range ballistic missiles can bring unique capabilities to the PGS mission. But these missiles are only uniquely capable if the United States must attack promptly, or within hours, of the start of an unanticipated conflict. In any other circumstance, the United States is likely to have the time to move its forces into the region. Hence, when deciding to fund the development of conventional warheads for long-range land-based or sea-based missiles, and whether to deploy conventional ICBMs, Congress may review whether the benefits brought by these systems outweigh the risks of misunderstandings arising from their use. This report will be updated as needed.