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  The US involvement in the Vietnam war began in early 1945 .The men parachuting into Pác Bó were led by Major Allison Thomas.
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  According to Eisenhower's domino theory, if communism were to be victorious in one nation , surrounding countries would follow like falling dominos.
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  The Geneva Accords brought an end to the First Indochina War. The ceasefire was signed and France agreed to withdraw its troop from the region. Vietnam was temporarily divided.
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  The Gulf of Tonkin resolution was a joint resolution that the United States Congress passed responding to the Gulf of Tonkin incident.
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  The Tet Offensive was a series of surprise attacks by the Vietcong on cities and towns throughout South Vietnam. It was considered to be a turning point in the Vietnam War.
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  The Mỹ Lai Massacre was the Vietnam War mass killing of between 300 and 500 unarmed civilians in South Vietnam
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  When the North Vietnamese tanks rolled onto the grounds of the Presidential Palace in Saigon in 1975, the Republic of Vietnam ceased to exist as a sovereign nation.The fallout of South Vietnam changed the way of life in the south and many people could not accept the new reality.