During both SALT I and SALT II negotiations the one airplane the Soviets feared most was the FB-111.
It was a superb penetration platform that could sneak in anywhere anytime and boom you before you knew it was there. The fliers loved it because of the relatively comfortable cockpit but they feared it because it could kill you if you gave it a chance. It was not overpowered by any stretch and if you got inverted with the wings swept your next of kin were notified later in the day.
If the terrain following radar (TFR) hiccupped, same deal. The next of kin wouldn’t even get your dogtags.
One F-111 that crashed was brought back in the back of a small pickup truck.