Members of the Iran's armed forces, some wearing ghilli suits, march during an annual military parade marking the 34th anniversary of outset of the 1980-88 Iran-Iraq war, in front of the mausoleum of the late revolutionary founder Ayatollah Khomeini just outside Tehran, Iran, Monday, Sept. 22, 2014.

Iranian Troops Move Into Syria As White House Blames Russia For Worsening Crisis

So far, direct Iranian military support for Mr. Assad has come mostly in the form of military advisers. Iran has also mobilized Shiite militia fighters, including Iraqis and some Afghans, to fight alongside Syrian government forces.