- financial: the forever wars of Iraq / Afghanistan are somewhere around, per google, 8 trillion dollars. In terms of global warming mitigation then (yeah, it would never have been spent on that) or in terms of opportunity costs of budgeting now and the near future, that is a huge loss. That is a quarter of the current US debt (31.5 trillion dollars). It is a almost a third of our annual GDP.

- freedom: it instituted dangerous protocols for surveillance, jailing of US citizens without trial, assassination of US citizens without trial (Obama), the "enemy combatant" designation, mainstreamed use of torture and extraordinary rendition. I'm no war historian, but I think the only other war that resulted in such massive expansion of federal government power, and the creation of agencies to exert such power, was WWII with the beginnings of the CIA and NSA. Did Vietnam or Korea result in such expansions and institutions?

- trust: granted we always had an iffy relationship with this with banana republic atrocities, supporting dictators, the Shah of Iran, etc, but Iraq really destroyed a lot of American standing worldwide, and considering the immediate aftermath of 9/11 was a surge of sympathy/support, that says something. America arguably lost a huge amount of it's soft power. Everyone knew it was an imperialist grab of oil by oilmen in charge of the White House. Consider that this was the early days of the EU and China was on the rise. Iraq likely lead to countries seeking leadership and aid from those rather than America as a serious option.