Where's the beef?
What's all this discussion about the SR-71, and what in tarnation does that have a tinker's damn to do with MIRVs!!!
The US "Star-wars" program was already designed to intercept MIRVs, because we and the Russians already have them. The Chinese have probably been embarrassed for years because they couldn't afford them. Now that they do, I wouldn't really call it any kind of advantage at all. We and the Russians got smart a long time ago and started reducing our warhead inventory. If China want's to repeat failed history - I say let them! It is now cheaper to build the interceptors than it is to build the MIRVs. We could have millions of interceptors for the price of a squadron of MIRVs. We will bury them economically, and not even fire a shot. No one - not even the Chinese - are crazy enough to pull that trigger.
I have seen many a test footage of intercept vehicles of various types, for 20 years now. Anyone who thinks they don't work is fooling them selves. We shot a nuclear powered SUV to Mars and hit what amounts to a nat's ass in a crater. You don't think we can intercept a warhead? I don't care if they are multiple warheads, I don't even care if they are independently targeted and even using deflection tactics - we can hit them with literally shot gun blasts of individually controlled intercept vehicles fired just like a giant shotgun in space - and WAY cheaper than a MIRV!!!