The fight over Amerli in eastern Iraq has been one of the most important battles against ISIS, and a coalition of unlikely partners successfully defended the strategically located town.

The response to ISIS's push against the town was likely formulated by Qassem Suleimani, the head of the Iranian Revolutionary Guards Corps' Qods Force and probably the Middle East's most effective operative. Suleimani leads the Guards' operations outside of Iran's borders, and has raked in a number of major strategic victories over the years.

He was also reportedly on the ground in Amerli:



Suleimani has never been content with hanging back in Tehran. He is a field commander, and his successes stem from his apparent willingness to be physically present in the midst of regional crises — as analyst Emile Hokayem tweeted, "Suleimani is effective partly [because] he is a professional fighter who lives like one and shows up on battlefield."

He frequently traveled to Iraq during the most violent years of the U.S. campaign in the country, and coordinated the country's Shiite militias even during a time when the U.S. would likely have arrested him if given the chance. And he keeps close watch over battlefield dynamics from afar as well. Suleimani was responsible for Hezbollah's strategy at the Battle of Qusayr, which kept a strategically crucial border city under the Assad regime's control and is perhaps the definitive confrontation of Syria's civil war, according to Dexter Filkins' 2013 profile of Suleimani.

Amerli could be a similarly decisive flash point in the fight against ISIS, and Iraq's army is hailing it as a "big achievement and an important victory." It's a mostly Shiite town about 100 miles to the north of Baghdad, just outside the borders of the Kurdish-administered section of Iraq and not far from the border with Iran. ISIS would likely have cleansed the city of its ethnic Turkmen, Shiite population, pushing its self-declared caliphate further to the south and east and establishing a beachhead in its fight against the Kurds and the Iranians — and the Baghdad government.

The town was secured thanks to "an unusual partnership of Iraqi and Kurdish soldiers, Iranian-backed Shiite militias and U.S. warplanes," according to The Los Angeles Times, which reported that Amerli was the first town to successfully withstand an ISIS invasion.

Suleimani's presence underscores the town's potential importance — and might hint at the degree to which Iran and the U.S. are coordinating their response to ISIS's advance through Iraq.

As this map from the Institute for the Study of War demonstrates, Iranian-supported Iraqi militias, the Iraqi military, and the Kurdish Peshmerga broke the ISIS assault with the help of U.S. airstrikes. The U.S. acted as a force multiplier for a number of Iranian-backed arm groups — at the same time that the head of the Revolutionary Guard's foreign operations was present on the battlefield.

Suleimani understands the potential significance of his presence during perhaps the biggest success that any of the region's militaries have had against ISIS. As University of Maryland researcher Philip Smyth notes, photos of Suleimani in Amerli were circulated by a web page affiliated with Hezbollah, the Lebanese Shiite militia, and one of Iran's most important proxy groups.

The photos reinforce Tehran's image as the one power capable of stanching ISIS's advance — something the U.S. may eventually be forced to acknowledge.