Just Cause

Just Cause is when the war must confront an unquestioned danger and the damage inflicted by the  agressor or the nation or community of nations must be lasting, grave and certain. There was no just cause for the Vietnam War, because we were actually in no danger. Vietnam was in peril of becoming a Communist nation, but that was technically a problem for them, not us. So really, there was no lasting, grave danger for our country, therefore we didn't have a cause for going to war in Vietnam.