For as long as Democrats have been calling on George W. Bush to impose a deadline for withdrawal from Iraq, the US president has refused to announce arbitrary timetables.

Now, Mr Bush has agreed with Nouri al-Maliki, the Iraqi prime minister, that a security agreement being negotiated between the countries refer to a “general time horizon”. Democrats interpreted the move as a U-turn, but the White House finessed the shift – which was at least semantically significant – by saying it reflected improved conditions in Iraq.