Not even really the latest, the high speed flight of the SR-71 was generally detectable enough that they could coordinate a fleet of MiG-25 interceptors basical

Not even really the latest, the high speed flight of the SR-71 was generally detectable enough that they could coordinate a fleet of MiG-25 interceptors basically on a timer to be in the vincinity of its flight path long enough for a radar lock. The resources expended to coordinate and fly such an intercept weren't really worth it for anything more than posturing, but it worked well enough to dissuade the US from doing any actual attempts to breach their airspace