The authority of the UN is further reduced, international law is brought into more contempt, the human rights of the Iraqi people suffer more grievous and gross violation, democracy is made more impossible than it was before, and the neighbours most friendly to the West are put in a more precarious position.
Occasional justice is no justice.
Human rights are not a stick with which to belabour your enemies, laying it aside for your friends. When Saddam Hussein used chemical and biological weapons against Iran and against Kurds he was aided and abetted by the West. Now he is a monster. There was a promise at the end of the Gulf War to move towards a Middle East free from weapons of mass destruction, but this has got nowhere. The effect of sanctions on Iraq has been catastrophic.