Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues [February 6, 2015] [open pdf - 455KB]
"Conventional prompt global strike (CPGS) weapons would allow the United States to strike targets anywhere on Earth in as little as an hour. This capability may bolster U.S. efforts to deter and defeat adversaries by allowing the United States to attack high-value targets or 'fleeting targets' at the start of or during a conflict. Congress has generally supported the PGS mission, but it has restricted funding and suggested some changes in funding for specific programs. CPGS weapons would not substitute for nuclear weapons, but would supplement U.S. conventional capabilities. They would provide a 'niche' capability, with a small number of weapons directed against select, critical targets. Some analysts, however, have raised concerns about the possibility that U.S. adversaries might misinterpret the launch of a missile with conventional warheads and conclude that the missiles carry nuclear weapons. The U.S. Department of Defense (DOD) is considering a number of systems that might provide the United States with long-range strike capabilities. […] While most analysts expected the Air Force to take the lead in deploying a hypersonic delivery system on a modified ballistic missile--a concept known as the conventional strike missile (CSM)--tests of the hypersonic vehicle known as the HTV-2 [Hypersonic Technology Vehicle 2] have not succeeded. An alternative glider, known as the AHW [Advanced Hypersonic Weapon], may be deployed on missiles based at sea. Congress may review other weapons options for the CPGS mission, including bombers, cruise missiles, and possibly scramjets or other advanced technologies.
CRS Report for Congress, R41464