It is highly doubtful a MiG-25 is just waiting up in the air for a plane to intercept and just happened to be going at it’s top speed. It is much more likely th

It is highly doubtful a MiG-25 is just waiting up in the air for a plane to intercept and just happened to be going at it’s top speed. It is much more likely they will have to scramble a few jets for the intercept. I believe that SR-71 didn’t fly over Russian airspace due to the U2 incident. It’s also likely an AWACs or two are around and could detect the jets scrambling.