Actually this is not correct. The Russians developed the Mig-31 Foxhound specifically to counter both our long range bombers and our high-speed reconnaissance aircraft such as the SR-71. Satellites are predictable (as their orbits are easily able to be calculated) so having the "surprise" capability of an SR-71 flight is not the same as having satellite coverage. Same reason we have the AF X-37B among other things that have not yet come out of the black. But as for nothing being able to touch the SR-71 (and don't get me wrong - it was decades ahead of its time and to this day is still an amazing aircraft):
Quote: "These deficiencies were settled when a more advanced MiG-25 development, the MiG-31, entered in service in the 1980s: the Foxhound was armed with a missile very similar to the US AIM-54 Phoenix, the R-33 (AA-9 Amos as reported by NATO designation). This weapon was ideal not only for shooting down the American bombers, but also to intercept and destroy fast reconnaissance aircraft, such as the SR-71.
This statement was dramatically confirmed in Paul Crickmore’s book Lockheed Blackbird: Beyond The Secret Missions.
In this book one of the first Foxhound pilots, Captain Mikhail Myagkiy, who had been scrambled with its MiG-31 several times to intercept the US super-fast spy plane, explains how he was able to lock on a Blackbird on Jan. 31, 1986:
“The scheme for intercepting the SR-71 was computed down to the last second, and the MiGs had to launch exactly 16 minutes after the initial alert. () They alerted us for an intercept at 11.00. They sounded the alarm with a shrill bell and then confirmed it with a loudspeaker. The appearance of an SR-71 was always accompanied by nervousness. Everyone began to talk in frenzied voices, to scurry about, and react to the situation with excessive emotion.” Myagkiy and its Weapons System Officer (WSO) were able to achieve a SR-71 lock on at 52,000 feet and at a distance of 120 Km from the target. The Foxhound climbed at 65,676 feet where the crew had the Blackbird in sight and according to Myagkiy: “Had the spy plane violated Soviet airspace, a live missile launch would have been carried out. There was no practically chance the aircraft could avoid an R-33 missile.”
After this interception Blackbirds reportedly began to fly their reconnaissance missions from outside the borders of the Soviet Union.
But the MiG-31s intercepted the SR-71 at least another time. On Sept. 3, 2012 an article written by Rakesh Krishman Simha for Indrus.in explains how the Foxhound was able to stop Blackbirds spy missions over Soviet Union on Jun. 3, 1986. That day, no less than six MiG-31s “intercepted” an SR-71 over the Barents Sea by performing a coordinated interception that subjected the Blackbird to a possible all angle air-to-air missiles attack. Apparently, after this interception, no SR-71 flew a reconnaissance missions over the Soviet Union and few years later the Blackbird was retired to be replaced with the satellites. Even if claiming that the MiG-31 was one of the causes of the SR-71 retirement is a bit far fetched, it is safe to say that towards the end of the career of the legendary spyplane, Russians proved to have developed tactics that could put the Blackbird at risk."