He will have to reshape policies on the widest imaginable range of challenges, domestic and international. He will need to rebuild productive working relationships with friends and allies. He must revitalize a flagging economy; tame a budget awash in red ink; reduce energy dependence and turn the corner on the truly existential issue of climate change; tackle the growing danger of nuclear proliferation; improve the defense of the homeland against global terrorists while putting more pressure on al Qaeda, especially in Pakistan; and, of course, manage two wars simultaneously.”