Conventional Warheads for Long-Range Ballistic Missiles: Background and Issues for Congress [Updated January 9, 2007] [open pdf - 210KB]
From the Summary: "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. […] 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."
CRS Report for Congress, RL33067