US presidents have a history of abandoning campaign promises by pointing out that “the world looks different from here” when they reach the Oval Office. A growing number of Democratic foreign policy wonks are hoping that Barack Obama will do just that with his Iraq election promises if he wins the race for the White House in November.

Having stuck to the line that he would withdraw one to two brigades a month and remove all US combat forces from Iraq within 16 months of taking office, Mr Obama’s promise is looking increasingly vulnerable to John McCain’s taunts of “surrender” as ­conditions in Iraq continue to improve.