Ayaz Gul ISLAMABAD— Pakistan has rejected as "utterly baseless" U.S. allegations that it still has sanctuaries for militants that are detrimental to Afghan and regional stability. In its biannual war assessment mandated by the U.S. Congress, the Department of Defense said that Taliban attacks in Afghanistan launched from sanctuaries primarily in the tribal areas of neighboring Pakistan remain a serious problem. The report goes on to assert that “Afghan- and Indian-focused militants” continue to operate from Pakistani soil to undermine…