Today is the deadline by which U.S. troops are to withdraw from major Iraqi cities. This clear line in the sand must provide some relief to many Americans, whose sacrifice has been extraordinary. But as the United States shifts its attention from Iraq to Afghanistan and other issues of grave importance, none of us can be lulled into believing that Iraq is a "mission accomplished." That sense of security is simply false. June 30 is not an historical endpoint to be celebrated by political philosophers; it is the beginning of a highly uncertain chapter in Iraqi democracy and self-governance. Recent painful events here demonstrate the challenges ahead. This month we had the sad task of burying one of Iraq's leading moderate politicians, Harith al-Ubaidi, who was brutally shot at a mosque June 12, probably at the hands of al-Qaeda. Large-scale violent attacks such as suicide bombings are down dramatically overall, but as two tragic incidents last week showed, they still occur and still sow chaos and despair. Countries in our region continue to attempt to influence our internal politics to their advantage; the continuing hold on power of the regime in Iran, for example, means continued Iranian support for sympathetic parties and groups in Iraq. Our country's trade minister resigned in May amid allegations of corruption that is reportedly so widespread in Iraq as to be on the scale of a second insurgency. Just this month, I was forced to take action against police officers accused of violating the rights of prisoners.