Official White House Photo/Pete Souza

Barack Obama makes a point to Hillary Clinton as they sit at a picnic table on the South Lawn of the White House in April 2009. They were barely one hundred days into the administration, an adjustment period that proved harder on Clinton than was evident at the time.

Official White House Photo/Pete Souza

Obama and Clinton negotiate with leaders from China, India, Brazil, and South Africa after crashing a meeting at the Copenhagen climate summit in December 2009. The deal on carbon emissions they extracted was paltry, but the bonding experience was important for their relationship.

Reuters/Dusan Vranic/Pool

Senator Hillary Clinton tours a U.S. Army barracks in Iraq in November 2003. “It was the kind of gesture that means a lot to a battlefield commander,” said General David Petraeus, who traveled from his field headquarters in Mosul to brief her on the state of the war.

Official White House Photo/Pete Souza

Hillary Clinton was frequently the only person standing between Richard Holbrooke and a White House that wanted to force him out. Here, Holbrooke briefs Obama in the Oval Office in May 2009, while Vice President Joseph R. Biden, Jr., and Clinton look on.

Official White House Photo/Pete Souza

Obama nicknamed his three top national security aides, Tom Donilon, John Brennan, and Denis McDonough, “the grim Irishmen.” In March 2011, he spoke to King Abdullah of Saudi Arabia, as Donilon (left) and Brennan listened (the third Irishman, McDonough, is not pictured).

Official White House Photo/Pete Souza

Obama gestures to his first chief of staff, Rahm Emanuel (left), during an Oval Office visit by Prime Minister Benjamin Netanyahu. Emanuel, who acted as Obama’s de facto chief adviser on Israel at the start of his administration, brought strong ideas about how to handle Netanyahu.

AP Photo/Ng Han Guan, File

Clinton confers with her top policy aide, Jake Sullivan, at a meeting in Singapore in 2009. A high school debate champion, Rhodes Scholar, and Yale-trained lawyer, Sullivan conducted the secret nuclear talks with Iran. “He ended up being invaluable,” she said.

Official White House Photo/Pete Souza

Ben Rhodes and the president on Air Force One, going over the draft of a speech to the nation that Obama would deliver from Afghanistan hours later. Rhodes’s influence went beyond speechwriting: He led the covert talks with Cuba that ended fifty-three years of estrangement.

Getty Images/Molly Riley/Pool

Obama puts his arm around Clinton after they spoke at a ceremony at Joint Base Andrews to welcome home the caskets of four Americans killed in Benghazi, Libya. It was the end of Clinton’s worst week as secretary of state, but only the start of her troubles with Benghazi.

AP Photo/Susan Walsh

Sidney Blumenthal arrives to testify before the House Select Committee on Benghazi on June 16, 2015. A longtime confidant of Hillary Clinton, Blumenthal sent her hundreds of emails with intelligence about Libya. When her private email server became a scandal, he was at the center of it.

Official White House Photo/Pete Souza

Obama and chief of staff Denis McDonough (left, with arms stretched out and a red folder tucked in the back of his pants), on an end-of-the-day walk on the South Grounds in September 2014. It was on such a walk that Obama told McDonough he was holding off on a military strike against Syria.

Official White House Photo/Pete Souza

Obama gathers his aides in the Oval Office on August 30, 2013, to explain his decision to seek congressional approval before striking Syria. The photo captures the tension: Dan Pfeiffer leans forward on the sofa, while Ben Rhodes slumps back, resting his head on a hand.

AFP/Getty Images

Clinton begins to respond after being lectured by Vladimir Putin, then Russia’s prime minister, at their first meeting after she became secretary of state, in March 2009. Her host, sitting in his Putin Slouch, listened briefly before ejecting the reporters and cameras from the room.

New York Times/Redux/Doug Mills

Obama announces the New START arms treaty with Russia at the White House on March 26, 2010, with Clinton next to him. For Obama, who got into the nitty-gritty of the negotiations, it was the high point of his effort to “reset” relations with Russia.

Reuters/Jim Young

John Kerry cultivated Sultan Qaboos bin Said of Oman, who became a key middleman for secret nuclear negotiations between the United States and Iran. Here, Kerry meets the sultan at his residence in Muscat in May 2013, while those talks were under way.

AP Photo/Pablo Martinez Monsivais

Clinton greets Aung San Suu Kyi, the Burmese democracy icon, at her home in Rangoon, as the president looks on. Obama’s visit in November 2012 was a farewell road trip for him and Clinton, three months before she left his cabinet and began planning her own political future.