Trump was tight with Erdoğan (who was, incidentally, tight with Putin) so of course he backed his buddy over some upstart insurgents without the money to fly to DC and jerk him off.
But Al-Assad is also tight with Putin, which makes Trump’s siding with Israel (which is also heavily dependent on Russia for net new immigrants and so a tentative ally) against Syria somewhat peculiar. That is, until you note that Iran is involved, and exists as its own pole within the Middle East that’s more allied with China than Russia and hostile to Saudi Arabia, which is loosely allied with Turkey and Russia, but which has been on bad terms with Iran for decades.