Lyndon Johnson was given authority by Congress to dramatically increase troop levels in Vietnam based on an event in the Gulf of Tonkin. The Congressional act that granted that authority was known as the Gulf of Tonkin Resolution. The actual event was, literally, just a blip on a radar screen. Johnson presented it as evidence of an attempt to attack a U.S. vessel. It was just a brief track on a radar screen that was most likely caused by a fishing boat. There was no attack. There was a great deal of hype spread about the need to “stop Communism” and the “domino theory”. The domino theory was an idea that if South Vietnam should fall, the other nations of Southeast Asia would then fall to communist aggressors like a row of dominoes. South Vietnam eventually succumbed but there was no subsequent radical change in the other nations in the area.
Ho Chi Minh said, early on in our military involvement, that we would kill 10 of his soldiers for every one of ours that died, and we would give up because we would not stand for that level of casualties. The ratio between our casualty level and theirs was never that high. At a meeting in Hawaii, a Marine general presented an intelligence report that was a compilation of data from the CIA and from military intelligence sources. Attending the meeting were Defense Secretary Robert McNamara and several top officials from the Department of Defense and the Pentagon. The report was brief, in terms of the normal length of military intelligence briefings. It indicated the pool of available soldiers for North Vietnam was about four million. McNamara was always a whiz with numbers, so he would not have needed a calculator to grasp the significance of that figure. It meant that, given the Pentagon estimate of two of their soldiers killed for every one of ours, and given that some of the casualties on our side would be allied soldiers rather than Americans, it would take more than 300,000 Americans killed to reduce the North’s pool by 20% (which was not likely to affect their willingness or ability to wage war). He knew the American public would never stand for that level of casualties. That meant that the war of attrition, which was the Defense Department’s strategy, was not going to work and would ultimately result for the U.S. That briefing was given in January 1966. It was many years and many casualties later before we finally pulled out. President Johnson and later President Nixon ran the war based on a strategy that the facts indicated would not succeed. They ignored that information because they believed that action based on that data would be contrary to what they wanted.
The decision to attack Iraq was made shortly after 9-11 (maybe before?) and that decision was made before the evidence was examined. The Bush administration used documents that supposedly showed Iraq was trying to purchase uranium from Niger to show that Iraq was developing nuclear weapons. In fact, the documents in question were forwarded to the U.S. intelligence community by the British, who said they believed the documents were fake. They were, indeed, fake, but the Bush people ignored that evidence. Colin Powell presented satellite photos to the U.N. that he claimed showed a mobile bio-weapons lab. The vehicle in question was actually a fire truck. Any evidence that indicated a war with Iraq was not necessary was simply shoved aside. The administration also claimed (and Dick Cheney still claims) that Iraq had close ties to al-Qaeda. That is just nonsense. These claims have been made by people who allow their ideology to drive their perception of reality. If the facts do not fit their pre-conceived notions, then the facts must be wrong. It is a blind and dangerous approach to foreign policy, or any other policy.