Throughout 2018, five key powers have competed for influence in the Syrian civil war -- Turkey, Russia, Iran, the United States and Israel. The interests of these countries have prevented further regional spillover from the conflict, but they have also sustained the government of Syrian President Bashar al Assad. As the conflict enters its final stages, the possibility of a breakout conflict involving one of the five overseeing powers is very real. As we go into the new year, we take a pictorial look back at Syria over 2018 and consider what 2019 holds, especially in the wake of U.S. President Donald Trump's Dec. 19 announcement of a U.S. withdrawal from the conflict....