United States Deputy Secretary of Defense Patrick Shanahan, who will take over for ousted Secretary of Defense James Mattis in January, has significant ties to the U.S.-Turkey arms trade— a concerning move as U.S. President Donald Trump supports Turkish president Recep Tayyip Erdogan's threats against Northeast Syria.

"I am pleased to announce that our very talented Deputy Secretary of Defense, Patrick Shanahan, will assume the title of Acting Secretary of Defense starting January 1, 2019. Patrick has a long list of accomplishments while serving as Deputy, & previously Boeing," Trump wrote on Twitter Sunday morning.

Shanahan joined Boeing in 1986, and worked there for over 30 years. He had no previous government experience when appointed Deputy Secretary of Defense. According to his official Department of Defense biography, he held notable roles "as vice president and general manager of the 787 Dreamliner, leading the program during a critical development period; as vice president and general manager of Boeing Missile Defense Systems, overseeing the Ground-based Midcourse Defense system, Airborne Laser and Advanced Tactical Laser; and as vice president and general manager of Boeing Rotorcraft Systems, overseeing the Apache, Chinook and Osprey." His final role with Boeing, before leaving for the Department of Defense, was as the company's senior vice president for supply chains and operations.

Shanahan's role overseeing Boeing Rotorcraft Systems is the most directly connected to Turkey's war against Kurds. The U.S. first announced the possible sale of CH-47F Chinook helicopters to Turkey in 2009, as part of a sale valued at $1.2 billion. The Defense Security Cooperation Agency (DSCA) noted the primary contractor would be Boeing Company of Ridley Park, Pennsylvania— a program that Shanahan had overseen.

Boeing's Turkey backgrounder reported that "in 2016, the governments of Turkey and the United States finalized the sale of 11 CH-47F Chinook helicopters through government-to-government channels. The initial order included 6 CH-47F Chinooks, which Boeing delivered in 2016 with the final delivery taking place in November 2016. The country also ordered 5 more Chinooks, bringing its total to 11 to be delivered through 2019."

The DSCA notice said that Turkey would use the helicopters to "meet current and future requirements for troop movement, medical evacuation, aircraft recovery, parachute drop, search and rescue, disaster relief, fire-fighting, and heavy construction....[and to] strengthen its homeland defense, deter regional threats, and improve humanitarian and disaster mobilization and response."

Human rights organizations— and the U.S. State Department itself— have noted the role of U.S.-made military equipment in Turkish atrocities for decades. The vast majority of planes and helicopters used by the Turkish Air Force are of U.S. origin. A 1995 State Department document, entitled Report on Human Rights in Turkey and the Situation in Cyprus, noted that U.S.-origin helicopters are "ubiquitous" in Turkey, and that there was little doubt they had been used to transport security forces perpetrating torture, arbitrary detentions, and enforced disappearances during the early 1990s.

Shanahan's oversight of Boeing's international supply chains has more indirect links to Turkish war crimes. A key supplier and partner of Boeing in Turkey is Turkish Aerospace Industries (TAI)— Turkey's state-run military and commercial aerospace company. TAI produces parts of several Boeing aircraft, as well as components of other Western-made aircraft that Turkey purchases— like the F-16s used to bomb Afrin, Shingal, and Makhmour this year alone. Boeing finds TAI valuable as a part of their supply chain, stating that "in April 2018, TAI was recognized as “Supplier of the Year” for its contributions to Boeing's success by sharing risk and supporting longterm relationships that promote and advance the company’s strategic objectives." The award was given less than a year after Shanahan left the supply chains and operations role at the company to assume his role as Deputy Secretary of Defense.

Trump claimed that he had discussed "expanded trade" during a bilateral phone call with Erdogan in a Tweet posted just thirteen minutes after the announcement of Shanahan's appointment, and the U.S. announced a $3.5 billion sale of Patriot missiles to Turkey earlier this week. The choice of a Secretary of Defense with Shanahan's background at this juncture suggests that the Trump administration plans to escalate American military support for Turkey— even as Turkish officials threaten to commit massacres in Northern Syria.

The United States has long been Turkey's largest arms supplier, and Turkey is one of the top 10 buyers of U.S. military equipment globally. Turkey also receives significant military aid through programs like the Section 1206 Train and Equip Authority, which supports foreign military forces in counterterrorism operations and military and stability operations in which the United States participates, and the International Military Education and Training program, which trains foreign forces.