Gulf of Tonkin incident

Most Americans know about the Vietnam War, but few actually know how the United States formally found itself involved. After Japanese occupation during the Second World War, France attempted to reassert her control over her colonies in Indochina. In 1954, the last remaining French fort was taken, and colonial rule was over, and the country was split in two, with the communist regime in the North, and an authoritarian regime in the south.

The United States had been providing military advisors and weapons. To the south, and by 1962, over 9,000 Americans were in South Vietnam. But in summer of 1964, things were being orchestrated to change. On August 2nd, 1964 the U.S. warship the Maddox fired upon three North Vietnamese boats, with “warning shots”. Aircraft flew over and badly damaged the Northern boats, and two days later the Maddox issued a report in which she claimed she was attacked by Northern ships, after conducting raids and sinking some more boats. 

President Johnson then asserted that the attacks on U.S. ships were unprovoked, which was false, and with the Gulf of Tonkin Resolution, Johnson could effectively do whatever he pleased, including declaring war, on any country in Southeast Asia, which they did.

This fabricated incident allowed the U.S. to do whatever it wanted in Vietnam. How many other wars are fought with false evidence?