In April 1970, the United States and South Vietnamese troops went to Cambodia to attack the communist bases and the supply lines. The U.S. eventually backed off by June 30, but the South Vietnamese stayed.

The actions of the South Vietnamese in Cambodia, and the air bombings of the U.S. to show support, along with villages being destroyed and civilians being killed, created sympathy for the Communists.

Later on time proved itself when the Khmer Rouge was led by Pol Pot in 1975 to seize control of the Phnom Penh and overthrow the United States. During this time most of the country's vehicles and machines were destroyed because the Khmer Rouge were against technology and Western influence. It is estimated that about a million and one half people were executed by the Khmer Rouge over the course of four years. They mainly attacked the upper class though, because they...