In Amerli, an unusual alliance defeated Islamic radicals. Don’t count on that lasting. - U.S. officials want a grand alliance to fight Islamic State. But Iraqi fighters in Amerli are turning on each other.

From The Washington Post:

AMERLI, Iraq — For weeks, Iraqi Kurdish fighters had joined an unusual alliance to free this dusty highway town besieged by Islamic State fighters. Shiite militias, Iranian trainers and U.S. military pilots had all contributed, finally wresting the city from the Sunni extremists and saving the 15,000 residents from starvation or brutal slayings.

But on Friday, as the Kurdish pesh merga fighters approached the city to greet the residents they helped save, they were treated less like liberators and more like intruders. “Pesh merga forces are not allowed to enter this city!” yelled a Shiite militiaman with Kataib Hezbollah, an Iraqi group. He waved his rifle at them and the pesh merga retreated.

“We fought for three months here, and now we have to fight these bastards,” said one of the pesh merga, who regard this area as part of their territory. “If this continues, we’ll have another war.”

“They are just like animals,” said a second pesh merga fighter. “They are mules.”

The Obama administration’s strategy in Iraq is predicated on the country’s competing militia groups, as well as its battered army, setting aside their differences over territory, ethnicity and religion to form a grand coalition to battle the radical Sunni members of Islamic State. The aftermath of the fighting in Amerli shows how quickly this hodgepodge of militia forces can turn on each other as they fight for influence and the spoils of battle.