Rebel groups supported by the United States are focused on toppling the Syrian president, Bashar al-Assad, not rooting out the Islamic State.
The United States is focused on defeating the Islamic State. While it has attacked 2,600 Islamic State targets, it has not directly attacked the Syrian government and it is backing rebel groups only with money, arms and some training.
Russia, Iran and the Lebanese group Hezbollah want to keep Mr. Assad in power, for now. Russia, in coordination with Syrian ground forces, has aimed the vast majority of its airstrikes at rebel positions.
The Islamic State, meanwhile, wants to both unseat Mr. Assad and create a caliphate stretching beyond Syria’s borders into Iraq and other countries.
I doubt anyone's goals are that straightforward or clear to the people adding more weapons. We must do something. Helping to blow people up is something.
Another something would be accepting refugees. Hahaha I kid.