Russia, China, and the United States are in a race to develop and deploy hypersonic glide weapons. Hypersonic vehicles are defined as moving at a speed greater than five times the speed of sound. The US Defense Department has claimed these weapons will provide revolutionary new capabilities and will present daunting new threats against which there is currently no effective defense. Such claims have been repeated with little skepticism in the public and trade press. Many of the claims made for hypersonic weapons are, however, overstated and much of what they can do could be accomplished more easily and cheaply using better-established technology, typically via the modification of ballistic missile warheads.