evidence: President Donald Trump used a lightning visit to Iraq -- his first with US troops in a conflict zone since being elected -- to defend the withdrawal from Syria and to declare an end to America's role as the global "policeman." [...] Morale-boosting presidential visits to US troops in war zones have been a longstanding tradition in the years following the September 11, 2001 terrorist attacks. .@FLOTUS Melania and I were honored to visit our incredible troops at Al Asad Air Base in Iraq. GOD BLESS THE U.S.A.! pic.twitter.com/rDlhITDvm1