Mr.Bush needs to do something far more difficult and more nuanced.He must begin to chart a middle course between an arbitrary exit timetable and an indefinite blank check.

• 布什先生面临的是一个更加困难和更加微妙的任务，他必须着手在武断的撤军时间表和含糊其辞的表态之间选择一条中间道路。