Report: Conventional Prompt Global Strike Weapons Face Challenges
Conventional prompt global strike, or CPGS, would have the ability to rapidly deliver — within minutes or hours — warheads armed with explosives anywhere in the world. Military leaders are interested in using them against "fleeting targets," or in areas that that are hard to reach, so-called anti-access/area denial scenarios.
While the United States already has the ability to quickly launch nuclear weapons, substituting them with conventional warheads is an idea that still being debated, said James M. Acton, a senior associate in the nuclear policy program at the Carnegie Endowment for International Peace, and author of the report, "Silver Bullet? Asking the Right Questions About Conventional Prompt Global Strike."
The program will have to contend with budget cuts, and officials still need to study the ramifications of a strategy that could unknowingly set off a nuclear war scare, he added.
Currently, three different types of CPGS weapons are being proposed. The first are land- or sea-based rocket-launched hypersonic gliders, also known as boost-glide weapons. The second are ballistic missiles launched from Ohio-class submarines. Lastly, there are air-launched hypersonic cruise missiles. The Pentagon currently favors the boost-glide systems, he said at a discussion of the report.
One of the biggest sticking points with CPGS is that a conventional weapon may be mistaken for a nuclear bomb, he said. Use of such weapons would likely "increase the risk of escalation in a conflict," said Acton
And there are ambiguities in other, perhaps even more important areas, he said. If the United States used non-ballistic weapons, there would also be questions about where the weapon was heading, and what exactly it was going to hit, such as conventional or nuclear weapon arsenals. That uncertainty could have serious ramifications, he said.
"Highly maneuverable boost-glide systems — and to an extent hypersonic cruise missiles — have ambiguity about where they are going to land," Acton said. "Countries observing them can't know where they are going to land because they are maneuverable, so this creates a risk that the United States is targeting another country."
Employing such weapons could be a double-edged sword, Acton said.
"There is a paradox here," Acton said. "Conventional prompt global strike may make war less likely, but should war occur, it could make escalation much harder to control."
Countries such as Russia or China, if they thought the United States was going to strike their anti-satellite weapons, could become hostile, he said. At the same time, there is preliminary evidence that both countries believe CPGS weapons would be effective, therefore making them less likely to attack.
The Pentagon needs to do more research before the military begins the procurement process of these weapons, Acton said. Particularly in a time of constrained budgets, the Defense Department needs to develop a scenario-based acquisition process and seriously consider if non-CPGS weapons may be more effective.
"If you don't look at this in a scenario-based way, there is a high risk of buying very expensive weapons that are not found to be very useful, because they just don't have the capabilities of dealing with specific scenarios in which you want to use them," said Acton. "In a time of fiscal austerity, focusing resources on the threats you think are most likely to arise and on the most effective way of combating those threats is the most strategic way forward."