Vital interest and the instruments of power
Causes of US failure in Vietnam include b) The United States supported corrupt leaders in Vietnam and d) Only a few US soldiers fought with honor.
One of the biggest issues of the Vietnamese war was that the United States went in because of anti-communism above all other reasons because of the Truman Doctrine. The South Vietnamese leaders were not well liked and were overall corrupt. The knowledge of this back home created a lot of public tension and actually caused soldiers to feel they weren't fighting for a good cause, or even commit war crimes as seen in the My Lai Massacre.
Hope I could help!
