Why has the Obama Administration ended efforts to train the Syrian Opposition?

Answer 1

The US was burned early in the Syrian Civil War when they tried to fund and train the members of the Syrian Opposition without properly vetting those groups that it armed. As a result, the US ended up funding Jubhat an-Nusra, the Syrian branch of al-Qaeda, which was part of the Syrian Opposition and, after being aligned with Islamic State for about a year, is again a part of the Syrian Opposition. When the American public found out that the US government was funding a branch of al-Qaeda, the people were outraged because al-Qaeda had been the very same organization that had attacked the US on September 11th.

As a result of this public relations scandal, the US decided to establish strict vetting procedures to figure out of the rebels that they would be training really believed in democracy. The vetting system only let in 60 fighters. This made it seem like another failure because the number people who could be vetted to want a secular democracy number so few. After training this 60 people, 20 died within the next few months, and the US has seen this as a lost cause.