Morton Halperin defends democracy:
As I argue in The Democracy Advantage, democratic governments are more likely than autocratic regimes to engage in conduct that advances U.S. interests and avoids situations that pose a threat to peace and security. Democratic states are more likely to develop and to avoid famines and economic collapse. They are also less likely to become failed states or suffer a civil war. Democratic states are also more likely to cooperate in dealing with security issues, such as terrorism and proliferation of weapons of mass destruction.
As the bloody aftermath of the Iraq invasion painfully shows, democracy cannot be imposed from the outside by force or coercion. It must come from the people of a nation working to get on the path of democracy and then adopting the policies necessary to remain on that path. But we should be careful about overlearning the lessons of Iraq.