If and when it goes down, it will go down in a way that Washington will consider catastrophic. Either someone will come to power that we don't like, or there will be enormous disruption to our oil supplies. Almost certainly, something bad will happen. The only thing we don't know is when. They're trading with Iran, and they want very much to resume trade with Iraq.
Turkey is one of the most outspoken proponents of lifting the oil embargo on Iraq.
It supported Saddam when he made his military incursion into northern Iraq last year. In the current crisis with Iraq over the U.N. weapons inspections, Turkey publicly stated that it does not support U.S. military action. They want Saddam in power, and they want Saddam to have control over the north. The answer is not very much. The same fallacy applies to Saudi Arabia and our other allies in the Gulf.