Defeating Terrorism in Syria

The Syrian war has raged for nearly 6 years. The regime of Bashar Assad, along with his backers in Moscow and Tehran, have pursued a policy of murdering anybody that expresses criticism of his power. Assad uses barrel bombs against anyone that is opposed to his regime. Half a million Syrian people have died, at least. Fifty thousand of those people, by all estimates, have been children. Five million Syrians have become refugees; 6 million are internally displaced. Terrorists, foreign fighters, rebels, and foreign governments, are all engaged in a battle for territory and control of different aspects of Syria. The state actors are divided into pro-Assad and anti-Assad actors. Additionally, there are terrorist groups on both sides of the conflict. Hezbollah, a terrorist group, is fighting for Assad; ISIS and Al-Qaeda, both terrorist groups, are are anti-Assad. In Syria, there are a multitude of actors all seeking to advance their own self-interests. The losers in this have been the Syrian people. What is the end game in the Syria? What is the national security interest of the United States? Should the U.S. ratchet up its involvement? Should the Middle East be left to resolve the conflict?