I’m not sure if you can say that the Vietnam war was “fake” in the sense of the weapons of mass destruction issue in the Iraq war. The United State got involved mainly to help out the French. Secondarily, the United States believed in a “domino theory” of communism – that if one country fell to it others would topple. Part of the worries about the world dominance of Russian communism seem odd from the post-Soviet perspective, but many Americans believed them at the time. The main issue with the war was that it was fundamentally unwinnable and the United States waited far too long to develop an exit strategy. I think the issue really was “stupidity” as the book depicts it, i.e. that the United States was not prepared for a guerilla war and did not have clear objectives, either tactically or strategically, resulting in many tragedies for both itself and the Vietnamese.