This is coolbert:
"Iran Deploys Forces to Fight al Qaeda-Inspired Militants in Iraq"
"The threat of Sunni extremists eclipsing the power of its Shiite-dominated Arab ally presents Iran with the biggest security and strategic challenge it has faced since the U.S.-led invasion of Iraq in 2003."
"With the Islamic State of Iraq and al-Sham, an offshoot of al Qaeda, rapidly gaining territory, Iran deployed Revolutionary Guards units to Iraq, according to Iranian security officials."
Al Qods force, Iranian Revolutionary Guards, Basiji Corps, Shia militias. Etc. The Shia does have considerable manpower resources available to combat the ISIL onslaught.