“At least 1,000 troops from Iran and the Iranian-backed Hezbollah were massing north of the key Syrian city of Aleppo in preparation for an attack on the rebels there, a U.S. senior defense official told The Daily Beast. The coming offensive—what the U.S. military called a ‘major push’—would be the largest Iranian intervention in Syria since the war began and the strongest sign yet of an increasingly coordinated military campaign by three of the United States’ military foes—Syria, Russia, and Iran.”
Source: Iran and Russia Ready to Pound Aleppo – The Daily Beast