As the Bush administration's envoy for Iraqi politics, Zalmay Khalilzad had considerable experience dealing with Iraqi opponents of Saddam Hussein. Before the war, Mr. Khalilzad was the White House's point man in meetings with Iraqi exile leaders in London and Kurdistan. After the shooting started, he was a key figure at political gatherings in Baghdad and at Tallil air base to begin assembling a new Iraqi leadership. So when the White House prepared to announce the appointment of L. Paul Bremer III as the chief civilian administrator in Iraq in May 2003, Mr. Khalilzad had every expectation that he would...