We have enough space junk as it is in orbit. I doubt they are going to fire an anti-satellite missile unless they are that desperate.
Unless they were desperate? If we had any sort of conflict with Russia or China the first thing they would want to do is totally wipe out our space assets. The US military is so heavily dependent on satellites for reconnaissance , GPS, etc it would cripple core services of the US.
We still have reconnaissance teams like FIST and Cav scouts and drones if you are going against a low tech enemy. The SR-71s were mainly used to fly over the USSR and look for things of great value like missile silos, weapon test sites, airfields, bases. Things you wanted to destroy as soon as possible. Stuff that and possibly SAM sites and short ranged ballistic missiles would be assigned to a satellite.
Okay so you are telling me that we should send in a ground based scout to look for mobile ICBM's and other high value targets inside Russia or China? I don't think so, that's what the SR-72 was designed to do.
If you want to go find a tank platoon or weapons cache in a barn then is a job for a drone or reconnaissance team.
Sure the SR-72 might be a drone, but is a big target for big missiles. Besides anyone can just make a better radar with a faster missile.
You are totally confusing tactical reconnaissance with strategic, which are two totally separate things.
The SR-72 travels at Mach 6 well above 120,000ft, which in theory would be in the combat envelope of the S-400. But a target flying at Mach 6 greatly reduces engagement time and the altitude also plays a factor. You also have to remember this thing would probably have a forget-load of ECM and active counter measures to ensure it's survival.
