When two Navy F-14 Tomcats engaged and shot down two Sukhoi Su-22 jet fighters in 1981, they drew on experience and tactics that they had learned from a previous encounter with MiG jet fighters. The difference between the two encounters was that in the first, the enemy fighters were flown by American pilots assigned to a top secret squadron hidden at a remote airfield in the ultra-secret Tonopah Nuclear Test range, Nevada. In the second, the Sukhoi fighters were flown by Libyan pilots attempting to enforce Colonel Qadaffi's 'Line of Death' over the Gulf of Sidra. From the mid-1960s until the end of the Cold War, the United States Air Force acquired and flew Russian-made MiG jets, eventually creating a secret squadron dedicated to exposing American fighter pilots to enemy MiGs.