The Iranians don’t hesitate to train fighters in Syria, per this Wall Street Journal report:
At a base near Tehran, Iranian forces are training Shiite militiamen from across the Arab world to do battle in Syria — showing the widening role of Iran’s elite Revolutionary Guard Corps in Syria’s bloody war.
The busloads of Shiite militiamen from Iraq, Syria and other Arab states have been arriving at the Iranian base in recent weeks, under cover of darkness, for instruction in urban warfare and the teachings of Iran’s clerics, according to Iranian military figures and residents in the area. The fighters’ mission: Fortify the Syrian regime of President Bashar al-Assad against Sunni rebels, the U.S. and Israel.
Iran’s widening role in Syria has helped Mr. Assad climb back from near-defeat in less than a year.