Yesterday’s overwhelming Senate vote to require detailed reporting to Congress on Iraq and make clear that the United States will not stay longer “than required” puts Iraq back on Congress’s agenda. There is now a strong bipartisan consensus that we need an exit strategy. But yet to emerge is the content of that strategy. We have two overriding objectives in Iraq: to facilitate a viable power-sharing agreement among Sunnis, Shiites and Kurds and to turn over responsibility for security to the Iraqis on a steady basis. Any exit strategy must address both issues in order to leave post-Saddam Iraq in...