[ Hypersonic weapons ]( http://www.theguardian.com/world/shortcuts/2014/aug/26/hypersonic-weapons-global-arms-race-us-tested-prototype ) now being developed by the US, China and Russia would put the world on a hair trigger and could even be mistaken for a nuclear attack. It would be smarter to sign a treaty to ban them, but the US government generally refuses, assuming it will have the advantage.
Ссылка: https://stallman.org/archives/2014-may-aug.html#27_August_2014_%28Hypersonic_weapons%29