Exporting democracy: what have we learned from Iraq?

Iraq has provoked the bitterest debate about American foreign policy since Vietnam. One rationale for the war proposed by the Bush administration was that it would lead to democracy--first in Iraq and then elsewhere in the Mideast. Many people thought that this was never a serious intention, but it is probably true that some members of the administration believed that the war would make democratization possible in Iraq. Four years later, most observers would agree that this effort has failed, despite the holding of several elections. Whatever you think of the Bush administration's motives, what is to be learned from the Iraq experience about the export--and import--of democracy?