Turkey protected ISIS leader Abu Bakr al-Baghdadi – and Trump should have known.In his national address announcing that US Special Forces had killed Baghdadi, President Donald Trump commended Turkey while turning a blind eye to Turkey’s collusion with ISIS. While Trump thanked “the Syrian Kurds for certain support they were able to give us,” he downplayed the importance of intelligence provided by the Syrian Democratic Forces (SDF), which was critical to the mission.We know that Turkey institutionalized support for jihadis after Syria’s President Bashar Assad attacked Syrian rebels in Ghouta using chemical weapons in September 2013, and that Turkey’s National Intelligence Agency (MIT) provided weapons, money and logistical support to jihadi groups that evolved into ISIS. Wounded ISIS warriors regularly showed up at Turkish hospitals in Gaziantep to receive medical care.Baghdadi founded ISIS in the spring of 2014. ISIS attacked Mosul and Sinjar in June, terrorizing Yazidis and Kurds. Over five years, the so-called ISIS caliphate grew to the size of Great Britain, with eight million people under its control.According to the SDF, “Turkey provides all kinds of support to the terrorist groups. These forces, trained and funded by Turkey, are engaged in a planned ethnic cleansing against our people.” Turkish-backed jihadis in the so-called Free Syrian Army (FSA) commit crimes on a daily basis in Turkish-occupied areas of Syria such as Afrin, Azaz, Bab, Jarablus and Idlib.In March 2019, the SDF drove ISIS out of its stronghold in Baghouz. From its interrogation of hard-core ISIS fighters, the SDF learned that Baghdadi had moved to Idlib in northwest Syria. Discovering Baghdadi in Idlib was a surprise to everyone who believed he was hiding in eastern Syria or western Iraq, near his ancestral village.Baghdadi ended up at a compound in Barisha just five kilometers from the Turkish border. The area around Barisha is controlled by the FSA. Dozens of Turkish military outposts are located near the border.A network of tunnels existed beneath Baghdadi’s Barisha compounded. All of the tunnels were sealed except for one. Since the tunnel network was destroyed by a US air strike, we do not know if the tunnel was an escape route leading to a nearby Turkish military base or to Turkey itself.Erdogan’s deal with Russia gives Turkey control of territory between Tel Abyad and Ras al-Ayn. The “safe zone” is supposed to be a destination for the repatriation of Arab refugees. However, Baghdadi was looking to reconstitute ISIS and viewed the safe zone as an Islamist sanctuary.In contrast to mounting evidence that Turkey protected Baghdadi, the Kurds were indispensable to the Baghdadi operation. US helicopters took off from Hareer Air Force Base outside Erbil in Iraqi Kurdistan. Incirlik Air Force base is much closer, but the Pentagon did not trust the Turkish government to make them a partner.Turkey’s Foreign Minister Mevlüt Çavusoglu exaggerated Ankara’s role by saying that “Turkey and our US counterparts shared information, exchanging opinions before the operation to kill [the ISIS] leader started. That’s why Trump thanked Turkey in his speech.”In fact, Turkey played no active role. According to a US official, “Turkey did not provide any assistance in this operation. [Baghdadi] was located right next to its border … That shows you how little they do on countering ISIS.” An Iraqi official indicated that Baghdadi was killed “after his hiding place was discovered when he tried to get his family out of Idlib toward the Turkish border.”The SDF, on the other hand, provided critical information. Mazloum Abdi, the SDF commander, heralded the “joint effort over more than five months between military intelligence of the SDF and US Forces.” He explained that they “documented over the past months the presence of high ranking ISIS leaders, including Baghdadi, in areas under control of the Turkish state.” According to Mazloum, “the operation was delayed for more than a month due to Turkish aggression in our region.”The US post-op report will reveal how Turkey, a NATO ally, colluded with Baghdadi over many years and protected him from capture. Ankara’s present leadership cannot be trusted. The SDF is America’s real friend in Syria – not Turkey.David L. Phillips is the director of the Program on Peace-building and Rights at Columbia University’s Institute for the Study of Human Rights. He was a senior adviser and foreign affairs expert at the US State Department during the Clinton, Bush and Obama administrations. His recent book is The Great Betrayal: How America Abandoned the Kurds and Lost the Middle East, and his forthcoming book is Front Line Syria: A Political and Military History of the Civil War.