Syria's conflict is the most violent to emerge from last year's Arab Spring, taking thousands of lives over the past 18 months.
After dictatorships fell in Tunisia, Egypt, Libya and Yemen, Syrian President Bashar Assad's government resorted to a brutal crackdown and mass killings to stay in power.
The United States has called for him to step down and has imposed economic sanctions. There is disagreement over what other steps the U.S. should take.
Assad long has helped Iran aid Hamas and Hezbollah, destabilizing Lebanon while threatening Israel's security and U.S. interests in the Middle East.
But extremists among the Syrian opposition, Assad's weapons of mass destruction and worries about Israel's border security have policymakers wary about deeper U.S. involvement.
- 10 things to know about corporate inversions
- Running again? Mitt Romney tells Hugh Hewitt...
- It's about time the government recognize the...
- Freelancers and millennials help usher in the...
- Obama tamps down prospect of strikes in Syria
- Student evades monitors, spreads Ebola to...
- John Lennon's killer: My life is all about...
- University of Phoenix founder dies, leaving...
- A New York Times article said Michael... 43
- Running again? Mitt Romney tells Hugh... 36
- 10 things to know about corporate... 32
- For the first time in American history,... 30
- Doug Robinson: When did Missouri turn... 24
- Why the poverty cycle is harder to... 15
- Obama tamps down prospect of strikes in... 14
- Winning plaintiffs in 3 states want... 14