Operation Rolling Thunder was a campaign of strategic bombing of North Vietnam conducted from March 1965 to October 1968. Ordered by President Lyndon Johnson, the operation was intended to bolster the morale of the South Vietnamese and limit the ability of North Vietnam to wage war.
Although limited American bombing had already been carried out against North Vietnam, the Johnson administration hoped that by escalating the bombing it could prevent North Vietnam from sending men and supplies to the Viet Cong in the south, damage North Vietnamese infrastructure and persuade the North Vietnamese to accept the South Vietnamese regime. The administration also wanted to supply a needed morale boost to the South Vietnamese government.
At first, air strikes focused on the southern part of North Vietnam, but the range of targets gradually increased until bombing raids were conducted all over the country, with exceptions for a buffer zone along the Chinese border and the cities of Hanoi and Haiphong.
Between 1965 and 1968, the U.S. military unloaded about 645,000 tons of bombs on North Vietnam. With the aid of the Soviet Union and China, North Vietnam created an effective air defense system and brought down about 900 planes. As a result, most of the U.S. prisoners of war in North Vietnam were pilots and other aircraft crew members.