In Iraq, the U.S. is fighting in a de facto alliance with one group on its list of terrorist organizations -- the Kurdistan Workers Party, also known as the PKK -- against another, Islamic State. This odd situation reveals an emerging truth about the Kurdish group: Its terrorist status is falling out of date. At this point it has to be recognized for the constructive role it can play in Iraq and the wider region.
On the front lines in northern Iraq, even before U.S. airstrikes began, the PKK proved itself to be the most effective fighting force against Islamic State (formerly Islamic State of Iraq and the Levant). Some of its battle units came from Iraq's Qandil mountains, long a base for PKK attacks into Turkey. Still more came from the Democratic Union Party, the group's affiliate organization in Syria, where they have fought Islamic State to a standstill in Kurdish areas.