Last August, Brunson’s 20-year-old daughter, Jacqueline Furnari, visited him in prison. By that point, he had lost 50 pounds. “He looked different, he sounded different. … It was really hard to see my dad like that,” she told me when we spoke on the phone. “I know he didn’t like having me see him like that. Kind of weak and broken and desperate.”

For Recep Tayyip Erdogan, the president of Turkey, Brunson’s case offered a chance to engage in a sort of hostage diplomacy. In a speech last fall, Erdogan appeared to link Brunson’s release to his demands for the extradition of Gulen by the Trump administration. (U.S. officials claim they have yet to receive adequate evidence to fulfill the request.) “‘Give us the pastor back,’ they say. You have one pastor as well. Give him to us,” Erdogan said, referring to Gulen. “Then we will try him [Brunson] and give him to you.”

Brunson’s ongoing incarceration also serves a clear political purpose for Erdogan. On April 18, his government called for snap elections, which are scheduled for June 24. Erdogan, who has led Turkey since 2002, seeks to capitalize on nationalist enthusiasm spurred by his recent military operations against Kurdish militants in northeastern Syria. He also hopes to further consolidate his power following last year’s constitutional referendum, which will concentrate governing powers under the presidency.

Erdogan may also need a convincing win at the ballot box before Turkey’s glum economic forecasts can incite a backlash among his supporters. With so much at stake, he knows he can rally the base by provoking Washington—and Brunson’s case gives him the means to do so. Standing up to the United States “is politically positive for any Turkish leader,” Howard Eissenstat, a nonresident senior fellow at POMED, a Washington-based think tank, told me. “The fact that the U.S. is outraged, the fact that there’s discussion of sanctions … reinforces the very things that many Turks find attractive about Erdogan."

Relations between Ankara and Washington began to falter when the United States started arming Kurdish militants in operations against the Islamic State in Syria. President Donald Trump’s decision to move the U.S. embassy in Israel to Jerusalem didn’t help the relationship. Then came the trial in New York of Mehmet Hakan Atilla, a Turkish banker convicted of helping Iran skirt international sanctions. In the coming months, U.S. authorities may impose sanctions on Turkish banks for their alleged role in facilitating Atilla’s maneuvers. They may also move to restrict the travel of Turkish officials they hold responsible for detaining roughly a dozen U.S. citizens currently held in Turkish prisons, including Brunson.

Turkey is also in the process of buying Russian-made S-400 anti-aircraft missiles. These missiles are incompatible with NATO-bloc defense systems, meaning that missile systems already installed in Turkey under the NATO umbrella would be unable to communicate with Russian-made systems. The purchase may heighten tensions between Turkey and Western allies, potentially leading to another round of sanctions. Additionally, U.S. senators have revived talks of blocking the transfer of more than 100 F-35 warplanes to Turkey—some of which Turkey has already paid for. Those talks originally began in response to a street brawl involving Erdogan’s security detail in Washington last May.