President Obama has asked Congress for $500 million to train and arm Syrian rebels. If approved, it would mark the most direct U.S. military role in the conflict to date, following more covert forms of support for the rebels. The request comes amidst growing concern about the influence of ISIS militants in both Iraq and Syria. Obama says the funds would go to “appropriately vetted” rebels who are fighting both President Bashar al-Assad and the ISIS militants.