Some people put the Iraqi civilian death toll in the hundreds of thousands, like 500,000. And US foreign policy created ISIS out of Al Qaeda. The US isn't guilty for what a dictator did, but our government is guilty of many things they have done directly. Like fail to tell Saudi Arabia it is bad to starve poor people to death who happen to be Shia and not Sunni. In that case US Gov isn't guilty for Saudi's actions but do have some responsibility to tell Saudis to stop and quit funding the military that is doing the starving.
Not sure how that relates to Venezuela though. The US military always has a "humanitarian" reason for interventions abroad. But you don't send in an army for humanitarian aid and you don't start a war without simple, clear goals and Congressional approval.