Causes of American Defeat in the Vietnam War Video

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  • 0:02 Background of the Vietnam War
  • 0:46 The Fear of Communism
  • 2:11 The Preparation of the…
  • 4:37 Domestic Instability…
  • 6:05 Lesson Summary
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Instructor: Christina Boggs

Chrissy has taught secondary English and history and writes online curriculum. She has an M.S.Ed. in Social Studies Education.

The outcome of the Vietnam War continues to be a hotly debated topic for historians and Americans alike. This lesson explores the various factors that contributed to American defeat.

Background on the Vietnam War

For many people, the Vietnam War is a black mark on American history. Beginning in the mid-1950s, the United States became increasingly involved in Southeast Asia, leading to nearly two decades of American support, and ultimately conflict, in Vietnam. Beginning with the American Revolution, the United States had grown accustomed to winning wars. The Cold War era, however, ushered in a string of American defeats in its fight to contain communism. U.S. defeat in the Vietnam War is attributed to a number of factors. The three we are looking at are:

  • A growing fear of communism
  • Under-preparation and failures of the American military
  • Domestic instability within the United States

The Fear of Communism

After years of fighting around the globe, World War II officially came to a close in September of 1945. As Europe and much of Asia struggled to rebuild, the U.S. and Soviet Union emerged as the world's two most powerful countries, each with a very distinct political, economic, and social ideology. The rising tensions between the democratic West and Soviet communism turned into a second global conflict as the two countries fought for ideological supremacy.

As you can imagine, American civilians and policymakers alike were more than concerned about the looming threat of communism. The Soviet Union was increasingly aggressive in Europe and Asia following World War II, beginning in 1948 with the Berlin Blockade, the Korean War in the early 1950s, and eventually the Berlin Wall in 1961. The Cuban Missile Crisis in 1962 further escalated American fears about the dangerous nature of communism.

This paranoia and fear fed into numerous theories and foreign policies. Among them was the domino theory. If one country in Southeast Asia (namely Vietnam) fell to communism, the entire region would surely topple under communist influence, much like a line of dominoes. Intervention in Vietnam became a matter of principle: the United States was committed to defend against the spread of communism anywhere in the world, no matter the cost.

The Preparation of the U.S. Military

One of the leading causes of American defeat was the chronic lack of preparation of the U.S. military. Beginning in the mid-1950s, the United States supported the shaky South Vietnamese government under Ngo Dinh Diem. At first, U.S. involvement was limited to just military advisers in the region, but as pro-communist activity in South Vietnam escalated, so did American intervention.

As of early 1961, the United States increased its number of military advisers and personnel in South Vietnam. By 1965, it was sending active combatants to the region. Within just four years, the United States had roughly half a million active military personnel in Vietnam.

The U.S. military learned very quickly that it was grossly under-prepared for a sustained war effort in Vietnam. At the onset, the U.S. military also failed to take into account the popularity of the South Vietnamese government. While the U.S. saw Ngo Dinh Diem as an asset in the war against communism in Southeast Asia, the people of South Vietnam disagreed. Diem was distant from the South Vietnamese. His government was characterized by corruption, bribery, and oppression. Diem and other Catholic government officials committed violence against South Vietnamese Buddhists, an act that created significant dissent in the country. As a result, many non-communist South Vietnamese aided the Viet Cong.

One of the most obvious areas of under-preparation stemmed from the climate and terrain in Vietnam. American troops struggled in diverse and harsh terrain of Vietnam. Thick jungles, rugged mountains, punishing humidity, and a long rainy season put the unfamiliar Americans at a distinct disadvantage against the Viet Cong, who were the South Vietnamese communist combatants, and the North Vietnamese troops who knew the region well.

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