ISTANBUL — Two months before Mosul and other cities in northern Iraq fell to the Islamic State last June, representatives of a Syrian rebel group called on the new U.S. special envoy for Syria with an outline of a plan to stop the extremists.
The group urged the U.S. to shift its focus to eastern Syria, where the Islamic State had emerged from Raqqa and other towns under its control and begun military operations to capture Deir el Zour province.