The Soviet Union is long gone, but Russia still has Soviet-designed aircraft on the frontline...

For nearly five decades, the US and its allies saw the Soviet Union as their greatest threat. The Soviet military's massive size and sophisticated weaponry made it one of the most powerful forces in history.

Thankfully, direct war between the Soviet Union and its NATO adversaries never happened. But that's not to say it never came close, and the Soviet and NATO militaries kept a close eye on each other.