Complex sentence: While the Chairman of the Joint Chiefs of Staff outranks all other military officers, he does not have operational command authority over the Armed Forces; however, the chairman does assist the president and the secretary of defense in the exercise of their command functions.
Split into simpler sentences: While the Chairman of the Joint Chiefs of Staff outranks all other military officers, he does not have operational command authority over the Armed Forces. However, the chairman does assist the president and the secretary of defense in the exercise of their command functions.