[img]http://d.yimg.com/a/p/ap/20100621/capt.779c2b177b7344bb98bef343093edc93-779c2b177b7344bb98bef343093edc93-0.jpg?x=130&y=90&q=85&sig=UnSuS7rDfjgSX2fxIoOCDw--[/img]AP - The top U.S. commander in Afghanistan has been summoned to Washington to explain derogatory comments about President Barack Obama and his colleagues, administration officials said Tuesday.