Arguments advanced later by retired U.S. Army Lieutenant General Philip Davidson suggest persuasively that even as Congress debated the Gulf of Tonkin Resolution, the North Vietnamese Politburo was deciding to send regular units of the Peoples Army of Vietnam (PAVN) into South Vietnam. Inexorably, America was moving toward a major confrontation in Southeast Asia. In the run-up to the presidential election, both military pressure and political chaos mounted in Vietnam. In late August, General Khanh, unable to govern, dissolved his government and replaced it with a junta composed of himself and generals Khiem and "Big" Minh; the arrangement lasted less than a month before Khanh replaced the junta with a civilian puppet regime. On 11 October, 1964, the Viet Cong attacked in Tay Ninh Province north of Saigon in regimental strength, producing heavy government casualties, and on 1 November they mortared Bien Hoa Air Base, killing five Americans and destroying five B-57 bombers.
The 1964 election produced a landslide victory for Lyndon Johnson, but the results were to prove more equivocal than they appeared. Many voted for Johnson because they were convinced that he would keep America out of war. Some, at least, voted for Goldwater because they believed that America was already at war - as indeed she was - and that his promise of swift and decisive action offered the best hope of avoiding embroilment in a long, bitter and indecisive conflict. In the summer of 1965, a saying circulating among officers and NCOs in the first wave of the U.S. military buildup in Southeast Asia neatly captured the irony of the situation: "They told us if we voted for Goldwater, we'd be at war in a year. I did, and I am!"
With a solid victory over Barry Goldwater under his belt, Johnson could face the problems confronting him with renewed strength and confidence. One of his first and most basic decisions was not to sacrifice his social programs for the war; he would pursue both at once: the guns and butter strategy. He was encouraged by the belief that the South Vietnamese insurgency would collapse without North Vietnamese support and by the notion that North Vietnam could be brought into line by measured, incremental applications of military might: the concept of graduated escalation. The first of these beliefs was at best half true. Though in the final analysis the Viet Cong were firmly under North Vietnamese control they had considerable operational and tactical autonomy; more importantly, the situation in South Vietnam had grown so chaotic by the autumn of 1964 that a communist victory with out direct North Vietnamese intervention was a very real near-term possibility. The second of these notions, graduated escalation, was a product of the New Frontier, owing more to the theories of business professors and political scientists than to the historical experience of war. Among its adherents was Robert Strange McNamara. Senior military officers instinctively rejected graduated escalation, just as they resisted his notion that the Department of Defense could be managed rationally by the rigorous application o quantitative management techniques. The generals and admirals had a point: war is a terribly inexact business, more subjective than objective and driven by irrational forces not subject to precise control. But they were ineffective in presenting their arguments and,more to the point, McNamara had a good press and the President's ear. Finally, Lyndon Johnson had another significant concern: the possibility that American involvement in Vietnam might prompt communist China to intervene, leading to a wider war. China was in the throes of Mao Tse-tung's Great Leap Forward, but the destructive consequences of Mao's policies were unclear and, in any case, the destruction of the 1937-49 Civil War had not kept China from intervening in Korea.