Turkish officials made a big deal of offering the US the use of Incirlik Air Base, not far from the Syrian border, for airstrikes against ISIS. Growing disagreements over how that base will be used, however, threaten to change things significantly.
The US was keen to get the base, and termed it a “game-changer,” but almost all of their airstrikes against ISIS in that part of Syria are being done for the benefit of the Kurdish YPG. This is a huge problem for Turkey, which didn’t like the US helping the YPG in the first place, and certainly doesn’t want them to get even more help.
If and when the creation of the “safe zone” in Syria happens, the air base will probably be used primarily to protect that. In the meantime, the base is likely to be of limited use, with the US using it mostly for limited strikes to areas not being directly contested.
Whether it remains that way is unclear though, with the US liable to use the base in “emergency” situations to back the YPG, and that will be a touchy subject for Turkey, which has been talking up fighting the Kurds in recent days.