NORTH VIETNAM On Jul. 23, 1965,  SAM (Surface-to-Air Missile) sites were first detected in North Vietnam on Apr. 5, 1965. The next month a U.S. Navy plane was lost to a SAM and the U.S. began a series of special missions named "Iron Hand" against the rapidly expanding missile sites. Most were near the Hanoi-Haiphong area, but Washington had exempted these from air attack.

However, sites in other areas were fair game. By the end of the year, 56 SAM sites had been located by U.S. reconnaissance aircraft. The Russian-designed and manufactured SA-2 SAM, supplied in quantity to North Vietnam during the South East Asian (SEA) conflict, shot down its first American aircraft, a USAF airplane, on July 23, 1965. The next month, a U.S. Navy airplane was shot down by a SAM. As a result, the U.S. initiated a series of special aerial missions, known as "Iron Hand", against North Vietnam to destroy SAM launch sites under construction.