Maybe it would work more effectively if things were decided democratically in the UN with no veto rights to anyone?

As for the US offensive war in Iraq, it'll probably go on for a decade or so. You freed people from Saddam to now irradiated country that is in the middle of a civil war and the infrastructure is destroyed or badly damaged. I'm not entirely convinced that the Iraqi people are better off now. As for Afghanistan, I never liked it how the Taliban seized the power there by force.