But, what they definitely don't teach you in school is that the autocratic leader the US backed was so unpopular even 9 years before the first US involvement that he would have been voted out had the fair elections been held in 1956. Backing a wholly unpopular leader is what doomed the US's involvement from the start.
I didn't mean to imply that what I learned was the whole truth. I honestly think that we all learn different parts of the truth and that what we learn has a different bias depending on where we are from. The Tet offensive was definitely the worst of the war combat wise but there was also napalm related casualties and permanent damage from chemicals. It was a war that should have been left to the Vietnamise instead we got involved, backed an unpopular leader and suffered the consequences.