I believe that the Vietnam War and the USA desire to kill and overthrow Castro is one of the things that the US have done that got people skeptical about them and with the Iraqi invasions and murder of Colonel Ghaddafi as well but aside that they have done a lot of good in the world and everyone makes mistakes but when you repeat them thenit seems something is really wrong.
I wouldn't say they did a lot of good, I would just say that they are making excuses to make few of their military equipment manufacturers rich.
They take the money from their citizens, create some weapons, create some trouble and some stupid unverifiable reason to invade and they don't think about it twice.
It ain't a mistake, they would figure it out by now, it never made any sense.
They knew what they were doing, they just have no reason to care.
Money will always mean more to them then other people's lives. That is a problem with US politicians.