The quagmire theory explains the cause of the United States involvement in the Vietnam War. The quagmire theory suggests that American leaders had unintentionally and mistakenly led the country into the Vietnam War. The theory is categorized as an "orthodox" interpretation of the Vietnam War.
History
The quagmire theory comes from David Halberstam’s account of the U.S. military policy in Vietnam, The Making of a Quagmire. According to Halberstam, a reporter in Saigon at the time, the said "quagmire" was a frustrating military and diplomatic dilemma.
The theory was more deeply developed by Arthur Schlesinger in his book The Bitter Heritage. According to the quagmire theory as described by Schlesinger, the quagmire metaphor represented the one-step-at-a-time process that the United States inadvertently became entrapped in the military and diplomatic swamp of Vietnam. Schlesinger detailed the process of American involvement in a war that was not really in the American interest and as a result of inadvertent decision making and false hope.
"In retrospect, Vietnam is a triumph of the politics of inadvertence. We have achieved our present entanglement, not after due and deliberate consideration, but through a series of small decisions. It is not only idle, but unfair to seek out guilty men. Each step in the deepening of American commitment was reasonably regarded at the time as the last that would be necessary. Yet, in retrospect, each step led only to the next, until we find ourselves entrapped today in that nightmare of American strategists, a land war in Asia--a war which no president . . . desired or intended."
Schlesinger believed the war to be a "tragedy without villains" and identified nationalism rather than communism as the most influential factor driving US involvement in Vietnam.