A complete drawdown would require slimming America's diplomatic mission, hiring a vast army of contractors - whose reputation in Iraq is worse than U.S. troops - or putting American diplomats in harm's way. U.S. officials should decide on the scope of diplomatic presence that's needed and then work with the Iraqi government to reach an understanding about how to protect diplomats.
Second, any American offers of help must fit squarely within the confines of American interests. Technical assistance that facilitates communication between the Iraqi army and the Kurdish Peshmerga forces in the north, for example, would serve American interest in maintaining stability.
It's not in American interests, however, to offer support that allows the Iraqis to rely on American assistance instead of building their own capacity to secure, defend and govern Iraq. This leads to the third point: The goal of America's presence in Iraq should be to put Iraqis in charge of their future in a way that integrates the whole of the country into a viable political entity. The makeup of the Iraqi state, its internal borders, allocation of hydrocarbons and continued sectarian tensions all continue to plague the country, and all require Iraqi solutions.
In order to avoid "snatching defeat from the jaws of victory," it's important not only to avoid making an abrupt disengagement from Iraq, but also to create the conditions so that in the future Iraq really can stand on its own.