BY AL PESSIN — The United States on Tuesday, August 31 at a formal ceremony in Baghdad will end its combat mission in Iraq and complete the U.S. military’s transition to an advisory and training role in support of Iraqi forces. That effort is to continue until the end of next year, but there are significant questions about what happens after that.

U.S. combat units recently rolled out of Iraq, bringing the number of U.S. forces below 50,000. The remaining troops are what the military calls advise and assist brigades. Their primary mission — to help Iraqi forces become more capable of providing sophisticated security.