Bomb shells as decoration in a resort in Luang Prabang. Image by Asienreisender, 2010
The American Vietnam War (1964 - 1975) was the third biggest war in the 20th century. 3.000.000 million Vietnamese lost their lives during the war, while 75.000 GI's American GI's were killed. There was also a lot of unrest in America itself, for millions of Americans were mobilizing against this war, and further millions of people in other western countries. There are a lot of documentaries and movies about this war - Apocalypse Now and Rescue Dawn are just two examples.
Not many people know that the war did not only happen in Vietnam, but also in Cambodia and Laos. That is because the war against Vietnam's two smaller neighbours has never officially been declared. But it caused more destruction there than in Vietnam itself. The consequence in Cambodia was the total breakdown of civil society and the four years lasting rule of Pol Pot's Khmer Rouge terror regime, which committed a genocide against the Cambodian population, killing two of the eight million Cambodian people. Before the American intervention Cambodia was among the most peaceful countries in the world.
By the way: the American Vietnam War is also called the 'Second Indochina War'. The 'First Indochina War' (1946 - 1953) was the French post-colonial war, when France tried and failed to reestablish 'it's' Indochinese colonies after the loss of the II World War.