ISIS Turning Old Enemies into Awkward Allies

US attacks joined with militia advised by Iran.

The most recent example came this weekend with the rescue of the Iraqi town of Amerli, a town that had held off a besieging ISIS army for more than a month. That siege was finally broken with a combination of U.S. airstrikes, Iraqi and Kurdish army units, and a Shiite militia.

The U.S. has repeatedly said that is not coordinating its efforts with Iran.

In addition, many Iraqi Shiites in recent years have gone to fight in Syria to defend the regime of President Bashar al-Assad, whose government U.S.-backed rebels have been trying to topple. Many of those Iraqis who opposed U.S. goals in Syria are now returning home to join Shiite militias to fight ISIS.

Now, Hezbollah is poised to battle ISIS in defense of Assad -- and all three are traditional enemies of the U.S.

Possibly more surprising is Saudi Arabia aligned with Iran in its fear that ISIS could destabilize the region and threaten the influence of both governments.

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