Prompt Global Strike (PGS) is a United States military effort to develop a system that can deliver a precision-guided conventional weapon airstrike anywhere in the world within one hour, in a similar manner to a nuclear ICBM. Such a weapon would allow the United States to respond far more swiftly to rapidly-emerging threats than is possible with conventional forces. A PGS system could also be useful during a nuclear conflict, potentially replacing the use of nuclear weapons against 30 percent of targets. The PGS program encompasses numerous established and emerging technologies, including conventional surface-launched missiles and air- and submarine-launched hypersonic missiles, although no specific PGS system has yet been finalized as of 2015.