The administration of U.S. president Richard Nixon was all too eager to grant the shah’s wish in exchange for Iran’s help balancing a rising Soviet Union. Nixon and his national security adviser Henry Kissinger visited Tehran in May 1972 — and promptly offered the shah a “blank check.” Any weapons the king wanted and could pay for, he would get — regardless of the Pentagon’s own reservations and the State Department’s stringent export policies.
That’s how, starting in the mid-1970s, Iran became the only country besides the United States to operate arguably the most powerful interceptor jet ever built — the Grumman F-14 Tomcat, a swing-wing carrier fighter packing a sophisticated radar and long-range AIM-54 Phoenix air-to-air missiles.
It’s fair to say American policymakers quickly regretted giving Iran the F-14s. In February 1979, Islamic hardliners rose up against the shah’s police state, kidnapping 52 Americans at the U.S. embassy in Tehran and ushering the return of Ayatollah Ruhollah Khomeini. The Islamic Revolution transformed Iran from an American ally to one of the United States’ most vociferous enemies.
An enemy possessing 79 of the world’s most fearsome interceptors.
For the next five decades, the United States would do everything in its power — short of war — to ground the ayatollah’s Tomcats. But the Americans failed. Through a combination of engineering ingenuity and audacious espionage, Iran kept its F-14s in working order — and even improved them. The swing-wing fighters took to the air in several conflicts and even occasionally confronted American planes.
https://nationalinterest.org/blog/the-buzz/irans-air-force-flies-american-made-f-14-tomcats-24750