Marine Gen. John Allen, the top U.S. commander in Afghanistan whose nomination to head NATO is on hold, is one of several high-ranking officers being investigated for ethical violations this year, a run of embarrassment for a military whose leaders once seemed almost untouchable. (Associated Press)

Marine Gen. John Allen, the top U.S. commander in Afghanistan whose nomination to head NATO is on hold, is one of several high-ranking officers being investigated for ethical violations this year, a run of embarrassment for a military whose leaders once seemed almost untouchable. (Associated Press)