GlobalPost reports: Divided by history, geography and God, Abu Mohammed and Abu Hamza both smoke Marlboro cigarettes and agree on one point: The war for Syria is also a war for Iraq.

Driven from their homes by the 2003 US-led war in Iraq, both men, now in their 40s, found refuge for themselves and their families in neighboring Syria.

Nearly a decade later, both are back in the country that once sheltered them.

But this time their wives and children are no longer with them. The men are not in Syria to flee a war, but to fight one. Abu Mohammed, a Sunni, is training rebels in Aleppo. Abu Hamza, a Shiite, is battling alongside President Bashar al-Assad’s forces in Damascus.

Their involvement in Syria is further evidence that the war is evolving into an extension of the Sunni-Shia violence that Washington unleashed when it toppled Saddam Hussein.

More from GlobalPost: Complete Coverage: Inside Syria

“People ask me why a Sunni Iraqi is fighting in Syria and I have a simple answer: ‘I am fighting in Syria to liberate my country, Iraq, from the pro-Iranian Shiite militia,” said Abu Mohammed, 46, dressed in military fatigues, with a short greying beard, cigarette in one hand, sniper rifle in the other.

Iraq, said Abu Mohammed, was now “occupied” by Shiite militias: The Mahdi Army, led by Iraqi cleric Muqtada Sadr who has long ties to Iran; the Badr Brigade, armed and trained in Iran and formerly the armed wing of the Islamic Supreme Council of Iraq; and Iran’s own Quds Force.

Abu Mohammed considers Syria’s Assad regime ― led by members of the Allawite sect, an ancient off-shoot of Shiite Islam ― to be another arm of Iran’s attempt to dominate the Sunni-majority Middle East.

Any war against Assad in Syria is thus a war against Iran’s proxies in Iraq. [Continue reading…]