Most of the USA's space weapons you see today have been around as concept or in practical tests for some time and the US hasn't built a new ICBM for decades. High altitude Nukes were detonated over the Pacific but once the public got word that nuclear tests and their fallout had entered the USA's 'food-chain' the green people started to get worried. Russians had their own cold war plans awell one of which was a Salyut space station which was to be manned with a gun and used to shoot satellites. During the 80s the US airforce tested an ASAT missile fired from an F15 to try to strike down a research satellite. Some argue GW's current missile defence plans are nothing more than the dusted off blueprints from Reagan's loved Starwars program, although its still debated how effective this missile shield will ever be.