For the eight years that Syria has been mired in a civil war that has claimed more than half a million lives, the U.S. and Turkey have been among the fiercest critics of President Bashar Assad's regime, arming his opponents and condemning his abuses.
In April 2017, and again a year later, U.S. President Donald Trump ordered airstrikes on Syrian targets as punishment for what the U.S. said was the use of chemical weapons. Both Trump and his Turkish counterpart, Recep Tayyip Erdogan, have described Assad as a "butcher" of his people.
Fast forward to late 2019, and Washington and Ankara's actions might yet help Assad regain his hold over most of pre-war Syria.