Why would any American support the U.S wars?

Why would any self thinking knowledgeable American support the United States wars that cost more than 2 billion dollars a day when we are already in debt to begin with? We went into Afghanistan to find Bin Laden which I agree with, but he disappeared into the dust and will never be found again, so we decide to stay there for the next decade. Then we invade Iraq based on faulty information and end up killing hundred of thousands of innocent Iraqi civilians (including tons of children, I know this because thanks to wikileaks and a friend who is in the Army who I just recently spoke to). Then we decide to stay there as well which happens to be the 2nd most holiest country in Islam, so of course that is going to spread more hatred throughout the region if we are on there land killing there people. So my question is, since the U.S. wars are such a joke and we as citizens of this great country have been constantly lied to over and over again, why would we support such a grave injustice? Why do so many people need to suffer for the acts of such a small minority that never represented any of the countries we invaded? Just a side note; I support the troops all the way, they aren't the ones who made this decision for Americans to go over there and fight. Old men in suits send young men to war for a certain ideology, and that I can not agree with.