The first of the Rolling Thunder strikes was on 2 March 1965, when 25 F-105s and 20 B-57s struck a North Vietnamese army (NVA) ammunition dump at Xam Bong, just a few minutes' flight north of the DMZ. As subsequent strikes moved north, the tactics of defense and offense improved. One of the first increments was the deployment of College Eye, a Lockheed EC-121D aircraft that orbited above the Gulf of Tonkin and controlled traffic, assigned strike aircraft to forward air controllers, warned of MiG attacks forming in the Hanoi area, and relayed immediate intelligence and communications.
In late July, a single McDonnell F-4C became the first victim of a NVA missile. Four days later, a flight of F-105s roared in against a SAM site and knocked it out of action. Strikes against missiles were dangerous, and also complicated. One rule of engagement was that a missile whose radar was in the search mode was immune to attack; as soon as the mode was switched to track, the missile site became fair game. The imposition of demanding a check on the already overloaded pilot probably accounted for a number of losses to the SAMs. The missiles were most effective only after passing some minimum altitude; below a few thousand feet they were still accelerating and still well below their capabilities. The obvious counter was to fly low, but that made the strike force an easy target for the 23-mm automatic anti-aircraft fire, responsible for most of the losses over the North in the early months of Rolling Thunder.
The USAF countered the missile threat with Iron Hand flights, a hunter-killer team of fighters called 'Wild Weasels'. At first, they flew aging F-100F two-seaters that had been modified with additional electronic equipment. They preceded the strike force by about five minutes, going into the target area deliberately to draw missile fire. The plan was that the 'Wild Weasels' would detect and evade a missile launched at them, while firing one of their own AGM-45A Shrike missiles to ride the enemy radar beam backward to its source.
As a weapon, the SAM was not too effective. The NVA fired about 180 of them during 1965, and shot down only 11 American aircraft. They were very effective in forcing the strike aircraft into an altitude envelope where they were more vulnerable to other types of anti-aircraft weapons.