President Donald Trump’s choice to be the top U.S. military officer, retired Air Force Lt. Gen. Dan Caine, endeared himself to the commander in chief through his military call sign, “Razin,” during a meeting in Iraq years ago.

The retired Air Force general announced as the next chairman of the Joint Chiefs of Staff by President Donald Trump after the abrupt Friday night firing of his predecessor is a respected career F-16 pilot who is described by current and former officials who served with him as a professional with a “strong moral center.