There is no overarching explanation for Obama’s successive Middle East failures, but there are a few factors worth considering: the increase in the number of asymmetrical conflicts, in which the traditional use of force is largely ineffective; increasingly blurred lines between difficult allies and intransigent adversaries; and major political differences between a centrist US president and a Congress that is dominated more than ever by extreme ideas.&nbsp;
奥巴马在中东问题上一再失策，其原因不一而足，但其中有几个因素值得关注：不对称冲突数量上升，传统军事干预已不再奏效；盟友越来越难对付，敌人越来越强硬，两者之间的界线越来越模糊；中间派的美国总统和史上最极端国会之间存在重大政治分歧，等等。