I can feel the sweat trickling down my face as gaze through a small hole in the wall of a building overlooking a large roundabout. The hole is barely two inches across but I can see most of the street and the surrounding buildings. Somewhere out there, among the burnt-out cars and rubble, Islamic State (ISIS) fighters are lying in wait. My eye is immediately drawn to movement in a window of an apartment block on the far side of the street.The rag of a white curtain has somehow come through the smashed window and is now flapping lazily against the side of the building.After I pull my face away from the wall and wipe the stress from my eye, I glance right at the comrade that’s doing guard duty with me. He is standing at a window we filled with half-bricks the night before. Syrian bricks are made from concrete but are flimsy and hollow.With one of the bricks stacked on its side, there was a convenient gap for the lad to stare out from.I had chosen my lookout position precisely because it wasn’t an obvious target and I wouldn’t cast a shadow.Suddenly there was a frightening “CRACK” which sent the young fighter tumbling onto his back. One of the half-bricks – barely half a foot from the man’s head – had exploded inward, sending two more bricks that were stacked above crashing to the ground.Less than a second later another bullet hit the wall high above the window.The effect wasn’t as devastating as the round punched a hole straight through the concrete, scattering white dust onto the ground. My comrade turned to me with flecks of concrete on his cheeks and burst out laughing.We’re in Manbij, a city where life is cheap and death a lottery. On the other side of the city an American friend of mine had been killed by an explosive as he cleared a building. An IED had taken his life, a tactic of random murder employed by the retreating jihadists.The IEDs and the constant sniper fire had taken over 300 Syrian Democratic Forces (SDF) lives. It would take months to finally clear the city and kill 4,000 of the ISIS fighters.I had gone to Manbij as a foreign volunteer with the SDF. I’ve spent years fighting ISIS all across Syria, first with the YPG (a Kurdish militia) and finally with the SDF (a multi-ethnic force).Both groups believe in secular democracy and have a strong relationship with the coalition. After we liberated Manbij, the local Arabs and Kurds helped create a town council which put power back into the community’s hands. After years of brutal Islamic extremism, the people of the city were given all kinds of freedom. As I waved the city goodbye, I drove past women tearing off their burkas. Local men were hugging SDF fighters, laughing and smoking.The next town to be taken for the coalition was a place called Jarralabus.As the SDF prepared to move North, the Turkish army supported by an assortment of Free Syrian Army (FSA ) groups invaded Syria. ISIS had been tipped off and fled without a shot being fired. The jihadist commanders weren’t stupid, they knew the reason for the intervention was simple: the Turkish government couldn’t allow the SDF, which is allied to the Syrian Kurds, anywhere near the border. On the pretense of fighting ISIS, the Turkish president, Recep Tayyip Erdogan, wanted to stop the rise of the Syrian Kurds.Not only is Turkey is fighting a war against the Kurdish PKK but it’s also going though a process of rolling back democracy. The authoritarian Turkish president has arrested opposition leaders, purged the army, arrested tens of thousands of civilians and introduced restrictive new laws. The rise of Syrian Kurds and their desire for democracy on the other side of the border has infuriated the Turkish government. Erdogan considers the YPG and PKK to be the same terrorist organization.If the Turkish intervention in Jarralabus was designed to stop the Syrian Kurds, their new plan is to start reversing Kurdish power altogether. The YPG has just started an assault on the ISIS capital in Raqqa. While the Kurds are battling in the south, the Turkish military is now bombing SDF positions in Manbij. The Turkish military has been assisting the FSA in taking back a small town called Al Bab west of the city. President Erdogan has publicly said that after the FSA has taken the town, he will assist them in attacking Manbij.Presumably his recent air-strikes were designed to soften up the city’s resistance.A resistance made up of thousands of Arabs, Christians and Kurds, not to mentions dozens of foreigners.These volunteers came from the UK, Israel, America and the world to battle the murderous ISIS, not the Turkish army.The coalition now finds itself in the absurd position of seeing two allies battling it out. Much to the joy of ISIS, which hopes the Kurds – their most vicious enemies – will roll back. Already the SDF has warned its assault on Raqqa could be derailed. To further drive a wedge between the Syrian Kurds and the West, Erdogan has issued an arrest warrant for Salih Muslim – a Syrian Kurdish politician – on trumped-up charges.I risked my life in Manbij, I saw my friends die and comrades wounded, just so we could see democracy return.Now Turkey wants to turn it into the next Allepo. The real battle is against ISIS. The fanatics thrive on division; we must unite behind the SDF and build a future for Syria we can all believe in.