Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. This Day in History: America Inches Toward Vietnam War by Catherine Maddux In the fall of 1961, President John F. Kennedy signed off on sending more U.S. military aid to Vietnam -- just a few hundred soldiers to train South Vietnamese soldiers. Kennedy was neither the first nor the last American president to confront the conundrum of the so-called domino theory, the idea that the Soviet Union (and Communist China) were seeking to expand their influence in Southeast Asia, first in Vietnam and then its neighbors. President Kennedy (R) meets with Secretary of Defense Robert S. McNamara and Chairman of the Joint Chiefs of Staff General Maxwell D. Taylor (L) in the Oval Office at the White House on Oct. 2, 1963. President Dwight D. Eisenhower addressed the "domino" metaphor in a speech in 1954 as it related to U.S. policy in Vietnam -- and wider concerns regarding Soviet expansion. "Finally, you have broader considerations that might follow what you would call the "falling domino" principle. You have a row of dominoes set up, you knock over the first one, and what will happen to the last one is the certainty that it will go over very quickly. So you could have a beginning of a disintegration that would have the most profound influences." From 1954 to 1975, four American presidents would have to contend with whether or not to deepen U.S. involvement in Vietnam's war over what turned out to be misguided fears of Soviet expansion. By the time the United States withdrew in 1975, 2.5 million Americans had fought in Vietnam. 58,000 of them died. U.S. paratroopers carry a wounded man on a stretcher into a waiting helicopter in Vietnam, May 7, 1966. Kennedy's decision 55 years ago Wednesday (Nov. 16, 2016) ultimately was one of many, made over many years -- culminating in a war that spawned street protests, ended the presidency of Lyndon Johnson, and was deemed a lost conflict.