The Air Force, they stated, would provide close air support for Army units operating in South Vietnam. The sustained bombing of North Vietnam began when circumstances changed in South Vietnam. On February 8, 1965, Operation FLAMING DART I launched tit-for-tat retaliatory bombings in response to enemy attacks on American installations in South Vietnam. Such an attack on the Pleiku Special Forces base resulted in limited air strikes against oil supplies and naval bases in North Vietnam. The strikes were intended to deter the enemy with the "potential" of American air power.
These circumscribed efforts gave Ho Chi Minh time to construct perhaps the strongest air defense network in the world at the time. Eventually, it included over 8,000 antiaircraft artillery pieces, over 40 active surface-to-air missile (SAM) sites, and over 200 MiG-17s, -19s, and -21s. Continued Communist ground action in South Vietnam brought the Air Force into the teeth of this network. Operation ROLLING THUNDER began in March 1965 and continued until October 1968. It was a frustrating air campaign marked by limits at every turn, gradualism, measured response, and, especially, restrictive rules of engagement. Doctrine drove the Air Force to strike against industrial web, but Air Force and Navy aircraft would be bombing a nation with a gross national product of $1.6 billion, only $192 million of which came from industrial activity. Like those of Korea, the industrial sources of North Vietnam's power were in China and the Soviet Union, beyond the reach of American air power.
ROLLING THUNDER's initial targets were roads, radar sites, railroads, and supply dumps. Because of bad weather the first mission of March 2, 1965, was not followed up until March 15. The Johnson administration did not permit attacks on airfields until 1967. SA-2 surface-to-air missile sites went unmolested; North Vietnam was permitted to establish SAM sites, and only after missiles were launched from them could they be attacked. Another rule restricted operations in a 30-mile zone and prohibited operations in a 10-mile zone around Hanoi. In 1965 and 1966 165,000 sorties against the North killed an estimated 37,000, but the war intensified in the South, with 325,000 American troops stationed there by the end of 1966.
In the summer of 1964, the JCS had proposed a list of 94 strategic targets as part of an intensified bombing campaign over which President Johnson and his advisers maintained careful control, assigning targets during Tuesday luncheon meetings at the White House. They doled out enough to pressure Ho Chi Minh but too many to prevent peace negotiations or to invite Soviet or Chinese intervention. Of the many bridges
