How did southeast asia's colonial history produce increased tensions in vietnam ?

Vietnam was under French colonial power for 6 decades. The French said it was their duty to civilize parts of SE Asia and Africa but that was not really their mission. They were making tremendous profit from the natural resources of the area. They would not allow the people of Vietnam to even use that name or associate with others in the region. Many times they used the labor of the Vietnamese not much better than slave labor. The French imposed taxation on wages (which were already miserably low), poll taxes on males, stamp taxes similar to what the British did to American colonies and commodities on their own rice wine and products used at home. Education was about the only thing that did improve for the Vietnamese. By 1940, the French were losing control of their colonies. Ho Chi Min led a 4 month siege on Dien Bien Phu French garrison. The French left the region after this which left Vietnam in a very unstable situation. The United States was afraid the Communists would take over and would remain to help for over 20 years.