and North Vietnamese military involvement in the war for South Vietnam. In January, MACV intelligence would learn that two new North Vietnamese Army regiments, the 32d and the 101st, had infiltrated the South and had initiated combat operations. Intelligence sources would also report the existence of another NVA regiment in the first stages of formation in Quang Tri Province. When added to a unit of similar size which had appeared in Kontum Province (II Corps Tactical Zone) in the final weeks of 1964, the new arrivals would raise to four the number of North Vietnamese regiments known to be operating on South Vietnamese soil.4
The pace of escalation would quicken in early February. The Viet Cong would attack a U.S. installation at Pleiku in the Central Highlands on the 7th. Eight Americans would die in this incident, over 100 would be wounded, and a score of aircraft would be either destroyed or damaged. President Johnson would react quickly to the Pleiku attack by ordering a series of reprisal air strikes under the code name FLAMING DART. Recognizing the possibility of surprise North Vietnamese air strikes against U.S. installations in Vietnam, Johnson would also order a Marine light antiaircraft missile (LAAM) battalion to Da Nang, the American base located closest to Communist airfields. Armed with Hawk missiles, the Marines would protect the growing Da Nang airbasc from which many of the FLAMING DART raids were to originate.
American reaction to the Communists' escalation would not be limited to the bombing of North Vietnam. Washington also would authorize the use of U.S. jet attack aircraft to engage targets in the south. On 19 February, U.S. Air Force B-57s would conduct the first jet strikes flown by Americans in support of Government of Vietnam ground units. Less than one week later, on the 24th, Air Force jets would strike again, this time to break up a Communist ambush in the Central Highlands with a massive series of tactical air sorties.6
While the events of February would serve to focus world opinion more sharply on the intensifying conflict already raging over Southeast Asia, March would prove the decisive month in terms of the commitment of American combat power to the war in Vietnam. On 2 March, the President would order the FLAMING DART raids replaced by Operation ROLLING THUNDER-a sustained air campaign against the Democratic Republic of Vietnam designed to escalate gradually in response to continued Communist military activities in South Vietnam. ROLLING THUNDER would constitute a transition from the earlier reprisal type raids to a continuing air campaign based upon strategic considerations.
Within a week after the first ROLLING THUNDER strikes over the North, the ground war in South Vietnam would also shift toward deeper and more active American involvement. On 7 March, the 9th Marine Expeditionary Brigade- the force which had been poised in the South China Sea since the Tonkin Gulf crisis of the previous August-would finally land at Da Nang to provide protection for the air base. Although the Pentagon would announce their mission as purely defensive, the Marines would become the first actual American ground combat battalions on hand for use in Vietnam. With that commitment, the stage would be set for a new and more dramatic phase of what was already becoming known as the "Second Indochina War."