Share This Article

 “Refighting the last war” ensured U.S. defeat

On April 30, 1975, Saigon, capital of the U.S.-backed Republic of Vietnam (South Vietnam), fell to the invading military forces of the Democratic Republic of Vietnam (communist North Vietnam), two years after the  withdrawal of American troops in the wake of the January 1973 Paris Peace Accords. America’s troop pullout and its subsequent drastic cuts in economic aid left the South Vietnamese military weakened and on its own when North Vietnam cynically violated the peace agreement in early 1975 by launching a massive invasion. The nearly 300,000 North Vietnamese Army troops, 1,100 artillery guns and over 300 tanks crushed the South Vietnamese defenders in barely four months of conventional combat, achieving ultimate victory in the Vietnam War. Although American combat troops were not directly involved in the South’s final, crushing defeat, by failing to prevent the communist North’s victory, the United States – after years of costly effort that included a decade-long major military intervention and 58,000 American deaths – had lost the Vietnam War.

Over the past four decades, legions of historians, analysts and pundits have put forth various reasons to explain why America lost the war in Vietnam. Many blame what they claim were General William C. Westmoreland’s inappropriate combat tactics in the crucial years of 1964-68 – his emphasis on enemy “body counts” and conventional operations instead of implementing effective counterinsurgency policies. Some blame the media, particularly their egregiously flawed reporting of the 1968 Tet Offensive that gave the false impression that the North Vietnamese battlefield disaster was a communist victory, thereby helping turn American public opinion against the war. Others simply claim the war was “unwinnable” from the outset, citing the corrupt, inept South Vietnam regime as “unworthy” of American support.

Although a number of factors and influences, domestic and international, contributed to America’s defeat in Vietnam, the overriding reason the United States lost the war was one that has often fueled nations’ losing military efforts throughout history: the fundamental error in strategic judgment called “refighting the last war.” As American military intervention in Vietnam ramped up in the early 1960s, U.S. leaders unwisely based the foundation of their strategy in the current war in Vietnam on America’s previous experience fighting to save an Asian nation under threat of a communist takeover: the “last war,” Korea, 1950-53.

In Vietnam, however, the Americans were determined to implement a strategy that avoided what they perceived as the principal mistake that had turned the Korean War into a bloody stalemate. Yet instead of a blueprint for victory, “refighting the last war” proved to be a strategy for failure.


Committed to a global policy of “containing” the spread of communism, America’s Cold War-era political and military leaders – for whom the Korean War had been a defining experience – perceived the “containing communism” situation in Vietnam as replicating that of the 1950-53 Asian war. Either ignorant of or willfully ignoring the profound historical, cultural and geopolitical differences between Korea and Vietnam, U.S. leaders saw only their superficial similarities: a communist “north” attempting to overrun a democratic “south”; powerful communist nations (China and the USSR) sponsoring a “northern” regime attacking a U.S.-backed “southern” regime; and, most troubling, the “northern” countries’ shared border with China that made them communist-controlled buffer states between China and Western-aligned Asian nations.

In 1950, the rising Asian power, Mao Zedong’s People’s Republic of China, had shown – dramatically and at great cost to the United States – that it possessed the capability and, more importantly, the will to intervene militarily if the defeat of the “northern” buffer state appeared imminent. In October 1950, four months after the Korean War began, President Harry S. Truman sent U.S. and United Nations combat units north across the 38th parallel dividing North and South Korea. Instead of merely “containing” communism, Truman sought to “roll back” communist gains in Asia through an effort to unify the Korean peninsula by force. His ill-advised invasion of North Korea, however, quickly prompted a massive Chinese military intervention that drove U.S.-U.N. forces back south of the 38th parallel. China’s entry into the Korean War prolonged the conflict by several years, led to horrific casualties on both sides, and produced a frustrating battlefield stalemate when the July 1953 armistice ended the fighting along the same front line that had existed when the war began in June 1950.

Above all, therefore, the fear of Chinese intervention in the Vietnam War dominated American leaders’ strategic thinking and thereby set the parameters governing U.S. ground combat operations throughout the conflict.


Principally to deny China an excuse to replicate its Korean War actions and intervene militarily in the Vietnam War, U.S. ground forces’ operations were restricted to the territory of South Vietnam. North Vietnam would remain “off limits” to U.S. and South Vietnamese ground combat forces throughout the war. This was also extended for most of American involvement in the Vietnam War to respecting the “neutrality” of the bordering countries, Laos and Cambodia, large portions of which as early as 1960 had, in effect, been invaded and occupied by North Vietnam to establish the Ho Chi Minh Trail – the main route of communist troops, weapons and supplies flowing into South Vietnam. (The limited 1970-71 U.S. and South Vietnamese ground operations in portions of Cambodia and Laos proved too little, too late.)

The restriction confining the ground war to South Vietnam did not apply to American aerial bombing. Indeed, North Vietnam and the Ho Chi Minh Trail were bombed extensively. Yet the bombing campaign, whose targets were tightly controlled by Washington, was not decisive in determining the war’s outcome.

Despite what seemed the most effective policy for keeping China out of the war, the long-term effect of confining ground operations within South Vietnam’s borders proved irretrievably fatal to any hope America had of winning the war outright. It meant that U.S. military commanders were never given a mission to win the Vietnam War, but only to prevent South Vietnam from losing it. The distinction is no mere exercise in semantics – it was the key element in the U.S. defeat. This reactive strategy placed American forces permanently on the strategic defensive. Although U.S. ground forces did conduct offensives within South Vietnam at the operational and tactical levels, America had surrendered the strategic initiative to North Vietnam, which was then free to set the tempo of the war by feeding troops and materiel into South Vietnam as it wished.

By choosing the strategic defensive, U.S. leaders created a “localized” war of attrition that would drag on as long as both sides possessed the will to continue. North Vietnam simply had to prolong its war within South Vietnam until the United States inevitably abandoned the conflict. In this clash of national wills, North Vietnam proved to be better armed. The communist dictatorship possessed the “weapons” it needed to persevere as long as it took to win: a ruthless disregard of casualties and total control of its captive population.

America lost the Vietnam War the moment its leaders chose to “refight the last war” by surrendering the initiative in the conflict to the North Vietnamese. 

Originally published in the January 2014 issue of Armchair General.

Share This Article

Citation information

Jerry D. Morelock (7/13/2024) Strategy for Failure: America’s War in Vietnam. HistoryNet Retrieved from
"Strategy for Failure: America’s War in Vietnam."Jerry D. Morelock - 7/13/2024,
Jerry D. Morelock 4/14/2017 Strategy for Failure: America’s War in Vietnam., viewed 7/13/2024,<>
Jerry D. Morelock - Strategy for Failure: America’s War in Vietnam. [Internet]. [Accessed 7/13/2024]. Available from:
Jerry D. Morelock. "Strategy for Failure: America’s War in Vietnam." Jerry D. Morelock - Accessed 7/13/2024.
"Strategy for Failure: America’s War in Vietnam." Jerry D. Morelock [Online]. Available: [Accessed: 7/13/2024]