Pentagon officials charged with targeting Islamic State in Syria are having some fun with their map of the region this week. That’s because they — finally! — have permission from the Turkish government to use the U.S. air base at Incirlik, Turkey, just 60 miles from the Syrian border. Until now, U.S. aircraft going after Islamic State forces in the Syrian desert needed to fly 1,000 miles from the Persian Gulf to get at a wily, well-entrenched enemy.

The Turkish government’s long-sought permission to use Incirlik comes at about the same time the United States is revving up the idea of creating an Islamic State-free zone along a swath of Syrian territory abutting the Turkish border.

The idea is not to officially declare and enforce a no-fly zone but to establish a looser safe zone that would “ensure greater security and stability along Turkey’s border with Syria,” White House officials told The Washington Post. The area, 68 miles long, would come under the control of moderate Syrian insurgents battling Syria’s government in a deadly civil war, the Post reported.

This anti-Islamic-State buffer zone is something Turkey sees as crucial for its defense (the Turks really wanted the full-blown no-fly zone), so it looks like a smart deal for both sides, even if it isn’t being described as a negotiated compromise.

If you’re wondering why the arrangement sounds a bit squishy, and overdue, well, that only hints at the political complexity of fighting in Syria. The lineup of friends and allies who are committed, or sort of committed, to helping the U.S. eradicate Islamic State includes numerous governments and countless militias, all of whom have their own concerns and agendas.

If everyone keeps their word, it will be a formidable team. But here’s why that’s not guaranteed: They don’t all agree on who’s the most dangerous adversary. That opens up far too much room for breakdowns in cooperation or even double-dealings.

Consider again that Pentagon map of Syria: to the east, the border area is currently in the friendly hands of the Syrian Kurdish YPG militia, which has worked closely with U.S. forces in the air to drive back the enemy from territory inhabited by Kurds.

To the west is the area where Turkey wants the safe zone, which would allow thousands of Syrian refugees to return home from Turkish territory. In theory, the U.S., along with Turkey and other allies, should be able to use air attacks to drive back Islamic State.

The challenge is that neither the Turks nor the Syrian Kurds consider Islamic State to be their most dangerous enemy. In fact, they are more worried about each other because the Syrian Kurds are aligned with Kurdish separatists in Turkey.

“Of course everybody should work together and has a joint interest in defeating Islamic State,” Aron Lund, editor of the website Syria in Crisis, told us. “The problem is that’s pretty much the only thing they seem to agree on.”

Adding another layer of complexity, many of the other militias on the ground in Syria that would be part of the team fighting Islamic State also have their own higher aim: fighting the brutal regime of Syrian strongman Bashar Assad. Syria’s civil war has killed more than 200,000 people and weakened Assad’s government in the capital, Damascus. Assad is on the defensive, potentially distracting his enemies from fighting with the U.S. against Islamic State.

If things go the way those Pentagon players hope, Turkey will stick with the U.S. and help open up that safety zone, dealing a battlefield defeat to Islamic State. Turkey will be able to encourage the flow back across the border of Syrian refugees, and also feel more protected from Islamic State terrorist attacks like one that happened last week.

Who patrols that safety zone? That’s another good question. The U.S. has been slow to train a force of moderate Syrian fighters, but there are actually thousands of fighters in Syria from different factions who can fill the void. Some were trained by U.S. allies or the CIA. Many also are more fixated on fighting Assad than Islamic State. It’s not yet clear who is the most capable or trustworthy.

This would be a much easier war to fight if there were just two sides. But with Turkey’s inclusion, the U.S. effort gets stronger. If the entire team holds together, the mission to destroy Islamic State in Syria has a fighting chance.