What Now in SYRIA? How President Trump s decision to pull U.S. troops from Syria has upended that nation's brutal civil war--and what it means for the U.S.

• Author: Smith, Patricia

In October, President Trump announced that U.S. troops would leave northeastern Syria, where they'd been helping in the fight against the terrorist group ISIS since 2015. Soon after, Turkish forces launched a long-planned invasion.

The decision to leave, cheered by many of the president's supporters, caused an uproar among Republican and Democratic members of Congress. By pulling out, the U.S. left Kurdish militias in Syria--which had fought side by side with Americans against ISIS--at the mercy of Turkey, which has a separate conflict with the Kurds.

The U.S. pullback also upended Syria's eight-year-old civil war, which had been largely winding down, and gave Syria's dictator a new opening to reassert his power over areas still held by rebels.

Here's what you need to know to understand the conflict in Syria and what the new developments mean for the U.S.

What is the Syrian civil war about?

The Syrian civil war began in 2011 as part of a broader democratic uprising in the Middle East known as the Arab Spring. The situation quickly escalated when President Bashar al-Assad responded to demonstrations with a violent crackdown.

The war that evolved out of that uprising has pitted the Assad regime against rebel groups ranging from moderates seeking to oust the longtime dictator to Islamic terrorist groups like ISIS. The war has killed more than 500,000 people and displaced half the country's prewar population of 22 million.

Before the war, Assad ruled ruthlessly and was known for harsh crackdowns against his opponents. Since the conflict began, he's believed to have used chemical weapons against his own people at least twice.

For a while, it looked like Assad would be defeated; in 2013, rebel groups held more than half of Syria's territory. But in 2015, Russia intervened in the conflict, sending troops to prop up Assad. That helped turn the tide, and the Syrian government retook control of much of western Syria. Experts say it's all but certain now that the Assad regime will remain in power.

The devastation in Syria has been massive. Many parts of the country have been reduced to piles of rubble. Basic services like water and electricity are spotty. And beyond the physical destruction, Syria's middle class has been destroyed, its members having fled or fallen into poverty, and many young men are dead or missing.

"It's fairly clear that Assad isn't going anywhere," says Mona Yacoubian, a Syria expert at the United States Institute of Peace, in...