I was talking to a friend of mine who's an engineer for the airforce. He told me that there's a system concept floating around that will be able to pre-emptively destroy hundreds of ICBMs well before the end of the boost phase--ie, before they get over international waters, or foriegn soil. He says that this weapon system is relatively simple, and will all but gaurantee a total or near-total incapacitation of enemy launch vehicles, and best of all, will work before existing satellite systems even detect launches. It also boasts something the current systems in developement lack--a psychological effect
I did some research and found a
link.
