In 2005, Iraq had begun to descend into U.S.-fueled sectarian civil war, and support for the war was in a free fall. Joe Biden had already begun recasting his vote to authorize the war as a mistake, though he blamed it on a private conversation he claimed he had with George W. Bush in which the president had assured Biden that he had not committed to the war and was open to resuming United Nations weapons inspections.
In 2006, Biden had already decided that he was going to seek the Democratic nomination for president in 2008 and wanted to find a way to distinguish himself from Barack Obama, who was set to run as an anti-war candidate. Biden also wanted to differentiate himself from Hillary Clinton as the man with a plan to end the war. With this in mind, he co-authored a plan to divide Iraq along sectarian lines with self-governing units for Sunnis, Shias, and Kurds. The plan, an ill-conceived attempt by Biden to recreate the partitioning of Bosnia, was widely ridiculed in Iraq and the Middle East. It gained no momentum in the U.S., except in the imaginations of anonymous Bush administration officials.