On a December night in 2011, a terrible thing happened on Mount Cudi, near the Turkish-Iraqi border. One side described it as a massacre; the other called it an accident. Several Turkish F-16 fighter jets bombed a caravan of villagers that night, apparently under the belief that they were guerilla fighters with the separatist Kurdistan Worker’s Party (PKK). The group was returning from northern Iraq and their mules were loaded down with fuel canisters and other cargo. They turned out to be smugglers, not PKK fighters. Some 34 people died in the attack. An American Predator drone flying overhead had detected the group, prompting U.S. analysts to alert their Turkish partners. The reconnaissance flight—which was first reported by the Wall Street Journal in 2012—and its tragic consequences provided an important insight into the very tight working relationship between American and Turkish intelligence services in the fight against Kurdish separatists. Although the PKK is still considered a terrorist organization by the United States and the European Union, its image has been improved radically by its recent success in fighting ISIS in northern Iraq and Syria. PKK fighters—backed by U.S. airstrikes—are on the front lines against the jihadist movement there, and some in the West are now advocating arming the group and lifting its terrorist label. Documents from the archive of U.S. whistleblower Edward Snowden that Der Spiegel and The Intercept have seen show just how deeply involved America has become in Turkey’s fight against the Kurds. For a time, the NSA even delivered its Turkish partners with the mobile phone location data of PKK leaders on an hourly basis. The U.S. government also provided the Turks with information about PKK money flows, and the whereabouts of some of its leaders living in exile abroad. At the same time, the Snowden documents also show that Turkey is one of the United States’ leading targets for spying. Documents show that the political leadership in Washington, D.C., has tasked the NSA with divining Turkey’s “leadership intention,” as well as monitoring its operations in 18 other key areas. This means that Germany’s foreign intelligence service, which drew criticism in recent weeks after it was revealed it had been spying on Turkey, isn’t the only secret service interested in keeping tabs on the government in Ankara. Turkey’s strategic location at the junction of Europe, the Soviet Union, and the Middle East made the future NATO member state an important partner to Western intelligence agencies going back to the very beginning of the Cold War. The Snowden documents show that Turkey is the NSA’s oldest partner in Asia. Even before the NSA’s founding in 1952, the CIA had established a “Sigint,” or signals intelligence, partnership with Turkey dating back to the 1940s. During the Cold War, the U.S. used bases in Turkey primarily to conduct surveillance against the “underbelly of the Soviet beast,” as one NSA document puts it. Today, it targets Russia and Georgia from Turkish soil, collecting information in “near real time.” Since the outbreak of its civil war, Turkey’s neighbor Syria has become a central focus of NSA surveillance.

David Furst/AFP/Getty Images

U.S. secret agents have also provided support to the Turkish government in its battle against the Kurdish separatists with the PKK for years. One top-secret NSA document from January 2007, for example, states that the agency provided Turkey with geographic data and recordings of telephone conversations of PKK members that appear to have helped Turkish agents capture or kill the targets. “Geolocations data and voice cuts from Kurdistan Worker Party communications which were passed to Turkey by NSA yielded actionable intelligence that led to the demise or capture of dozens of PKK members in the past year,” the document says. The NSA has also infiltrated the Internet communications of PKK leaders living in Europe. Turkish intelligence helped pave the way to the success by providing the email addresses used by the targets. The exchange of data went so far that the NSA even gave Turkey the location of the mobile phones of certain PKK leaders inside Turkey, providing updated information every six hours. During one military operation in Turkey in October 2005, the NSA delivered the location data every hour. In May 2007, then-Director of National Intelligence Mike McConnell signed a “memorandum” pledging deeper intelligence support for Turkey. A report prepared on the occasion of an April 2013 visit by a Turkish delegation to NSA headquarters at Fort Meade indicates that cooperation in targeting the PKK had “increased across the board” since then. That partnership has focused overwhelmingly on the PKK—NSA assets in Turkey collected more data on PKK last year than any other target except for Russia. It resulted in the creation of a joint working group called the Combined Intelligence Fusion Cell, a team of American and Turkish specialists working together on projects that included finding targets for possible Turkish airstrikes against suspected PKK members. All the data for one entire wave of attacks carried out in December 2007 originated from this intelligence cell, according to a diplomatic cable from the WikiLeaks archive. The deep working relationship has continued under Barack Obama’s presidency. In January 2012, U.S. officials proposed supporting Turkey in their fight against the PKK with diverse measures, including access to a state-of-the-art speech recognition system that enabled real-time analysis of intercepted conversations. The system can even search for keywords and identify the person speaking if a voice sample of that individual has been stored. The NSA offered to install two such systems for Turkey’s intelligence service. In exchange, the Turks would provide voice samples for a number of Kurdish activists. Given its close and enduring relationship with the NSA, agency authorities wrote, they saw little risk in providing the technology. The only thing NSA experts didn’t feel comfortable entrusting to Turkey was the automatic keyword search function. The partnership is managed through the NSA’s Special Liaison Activity Turkey (SUSLAT) office, which is based in Ankara. In addition to data, the Americans provide their Turkish partners with complete interception systems, decryption assistance, and training. Using its internal “follow the money” reconnaissance unit, the NSA also tracks PKK’s cash flows in Europe. The Turks reciprocate by providing the U.S. agents with written transcripts of telephone calls made by PKK leaders, as well as intelligence insights about Russia and Ukraine.

Burhan Ozbilici/AP