WASHINGTON — Brett H. McGurk, President Obama’s lead negotiator in a secret prisoner swap with Iran, choked up as he boarded a Swiss government jet in Geneva on Sunday night and greeted three Americans who had just arrived from years of detention in Tehran. More than anyone else, he was responsible for their freedom.
“It was an incredibly emotional moment,” he said.
For a 42-year-old lawyer who began his career in the George W. Bush administration, it was also a remarkable professional triumph — another chapter in a career that has prospered through Republican and Democratic administrations, survived personal scandal and kept him at the heart of America’s most tangled relationships in the Middle East.
Even as Mr. McGurk was meeting furtively with Iranian officials over 14 months to negotiate the release of the Americans, he was leading a very public campaign as Mr. Obama’s special envoy to the global coalition fighting the Islamic State. He continues to be deeply involved in the complex politics of Iraq, which he first encountered as a young legal adviser to the Coalition Provisional Authority, the American civilian administration that ran Iraq in the months after the 2003 invasion.
“He’s a doer, who is nonideological, pragmatic, which very much meshes with the president’s approach,” said Benjamin J. Rhodes, the deputy national security adviser. “Over the years, the president has come to trust Brett’s judgment on things.”
Mr. Obama stood by Mr. McGurk even after the disclosure of steamy personal emails between Mr. McGurk and a correspondent for The Wall Street Journal, which derailed his nomination to be ambassador to Baghdad in 2012. Facing resistance from Republicans on Capitol Hill, Mr. McGurk withdrew his name. But the White House found him a job at the State Department working on Iraq and Iran, and Mr. McGurk later married the journalist, Gina Chon.
Since then, Mr. McGurk has played a central role in three of the administration’s most sensitive diplomatic efforts in the region: helping to broker the transition to a new Iraqi government in 2014, holding together a 65-country alliance to combat the Islamic State in Iraq and Syria, and leading the secret talks to free the Americans held in Iran.
Mr. McGurk’s peripatetic travel schedule as special envoy allowed him to moonlight as a negotiator for the Americans held in Iran, since he could easily arrange trips to Geneva for meetings with Iranian security officials. At midnight on New Year’s Eve, he recalled sitting across from his Iranian counterpart, trying to hammer out the sequence under which the United States and Iran would release their prisoners. From his window in the InterContinental Hotel in Geneva, there was a dazzling view of fireworks exploding over the lake. He did not stop to look.
“We barely budged,” he recalled.
It was the final stage of a grueling diplomatic odyssey. The deal almost fell apart at the last minute over a dispute with the Iranians about allowing the wife and mother of one of the freed Americans, Jason Rezaian, a reporter for The Washington Post, to board the plane with him in Tehran. To make sure that snag was resolved, Mr. McGurk stayed on the phone with a Swiss diplomat who was standing on the tarmac in Tehran, relaying updates to him about each of the Americans as they got off an airport bus and on the plane.
Mr. McGurk’s career traces the arc of American involvement in Iraq. A graduate of Columbia Law School who was a clerk for Chief Justice William H. Rehnquist, he arrived in Baghdad in January 2004, when the war effort was at a low ebb. He helped draft an interim Constitution for the incoming Iraqi government, an experience that gave him an expertise in Iraq’s feuding political factions.
Mr. McGurk was later transferred home to serve as the director for Iraq on the National Security Council. In 2006, he came to President Bush’s attention after being one of the first to advocate a surge of American troops into Baghdad to stabilize what he called a “disintegration” in security. Mr. Bush made Mr. McGurk the lead negotiator of the Status of Forces agreement, which set a timetable for the withdrawal of troops from Iraq by the end of 2011.
“He had that combination of knowledge and passion, and then a prodigious work ethic,” said Peter D. Feaver, a professor of political science at Duke University who worked with Mr. McGurk in the Bush administration. “This is also why an N.S.C. staffer tends to burn out.”
“What is impressive about Brett is not just what he has done,” Mr. Feaver added, “but how long he has done it.”
When Mr. Obama came into office in 2009, he kept on Mr. McGurk as one of a handful of Bush political appointees, and Mr. McGurk subsequently returned to Baghdad for unsuccessful talks to leave a residual American military presence in Iraq after 2011.
Mr. McGurk got a firsthand view of the chaos in Iraq after the departure of American troops. In June 2014, he was in Erbil, in Iraqi Kurdistan, when Islamic State fighters overran Mosul, Iraq’s second-largest city, and began to advance on Baghdad. He oversaw the evacuation of 1,500 Americans from Baghdad and later helped negotiate the transition from Prime Minister Nouri al-Maliki to a new government led by Haider al-Abadi.
“That was a very intense period,” Mr. McGurk said. But he said the Iran negotiation presented a different set of challenges. “This just had such a human dimension,” he said. “It’s very rare to have something this human.”
Mr. McGurk’s record in Iraq is not without blemishes, according to critics. During the period he worked on Iraq and Iran at the State Department, the Islamic State established a foothold in Syria and conquered large parts of Iraq. Mr. McGurk, they said, did not put enough pressure on Mr. Maliki to make his Shiite-dominated government more inclusive or to stem abuses by the Iraqi security forces — failures that helped create the conditions for the rise of the Islamic State.
The problem, some critics say, is that the administration ended up relying too much on Mr. McGurk to handle its dealings with the Iraqi government. “As the U.S. troops drew down from Iraq, you had a real shift away in attention from Iraq,” said Sarah Margon, the Washington director of Human Rights Watch. “Brett was able to retain his role as the point person, without a lot of oversight.”