Vietnam is a small country in the Eastern part of Asia. Popularly also called Indo China, it was part of The French Empire. But the equation was disturbed with the invasion by the Japanese Army during the Second World War. The French had no option but to retreat and they soon gave up in Indo China.
The Atomic Bombing of Nagasaki and Hiroshima (1945) altered the power equation further. The Japanese surrendered and the French tried to make a come back. But they were badly defeated by the communists under Ho Chi Minh and his commander General Giap. The entire NorthVietnam was taken over by the communists while the Southern part remained free of their influence. However a insurrection aided by the Communists from the North was started in South Vietnam.
The power vacuum was filled by the United States, which moved into the South with a vast Army to bolster the regime in South Vietnam. The aim of the USA was to stem the communist influence and for this they positioned almost half a million troops in Vietnam. In addition the US president LB Johnson, after the famous Tomkin Gulf incident ordered the aerial bombardment of military targets over North Vietnam.
The bombing from distant American airbases with heavy B 52 bombers failed to yield the desired results. The war in South Vietnam also failed to take off and the Communist guerrillas (The Viet Cong) harassed the US Army. There were daring attacks against the US troops and after a couple of years the American top brass realized that they could not win the war in Vietnam. In addition thelarge number of coffins arriving from Vietnam swayed public perception of the war at home in America and the Americans longed for a face saving way to get out of the war.
The war now became a quick sand for the US troops as the US Army realized that fighting on the flat plains of Europe and the Desert sands in North Africa was a different kettle of fish from fighting against the Guerrillas in the thick jungles of SE Asia. The harassed US Army despite tremendous acts of Individual bravery had no option but to call for a withdrawal from South Vietnam. It was a tremendous strategic defeat for US Arms. In fact just after the US withdrew the North Vietnamese over ran the south and established a communist regime there.
With the US involved in a similar fight in Afghanistan, there is a real possibility of a second straight defeat there after Vietnam. The Americans lost in Vietnam because of their lack of will to fight at the later stages of the war. It must be remembered the US forces while in Vietnam did blunt the famous Tet offensive in 1968. There subsequent loss of nerve was their undoing.
The war in Afghanistan is also similar. There are no easy victories and the US will have to show purpose and will to fight in Afghanistan. A loss of nerve like in Vietnam may well hand the US armed forces a defeat. The US Military leadership should be aware of this.