Hillary Clinton served as the 67th United States secretary of state, under President Barack Obama, from 2009 to 2013, overseeing the department that conducted the foreign policy of Barack Obama. She was preceded in office by Condoleezza Rice, and succeeded by John Kerry. She is also the only former First Lady of the United States to become a member of the United States Cabinet. As secretary of state she traveled widely and initiated many diplomatic efforts on behalf of the Obama administration.

Clinton established the Quadrennial Diplomacy and Development Review in 2009. She responded to the Arab Spring by advocating the 2011 military intervention in Libya, but was harshly criticized by both Republicans and Democrats for the failure to prevent or adequately respond to the 2012 Benghazi attack. Clinton helped to organize a diplomatic isolation and a regime of international sanctions against Iran in an effort to force it to curtail its nuclear program, which eventually led to the multinational Joint Comprehensive Plan of Action in 2015.

The strategic pivot to Asia was a central aspect of her tenure, underscoring the strategic shift in U.S. foreign policy focus from the Middle East and Europe towards Asia. She had a key role in launching the United States Global Health Initiative, which aimed to increase U.S. investment in global public health, including combating HIV/AIDS, tuberculosis, and malaria. Her use of a private email server as secretary was the subject of intense scrutiny; while no charges were filed against Clinton, the email controversy was the single most covered topic during the 2016 presidential election.

Nomination and confirmation

Within a week after the November 4, 2008, presidential election, President-elect Obama and Clinton discussed the possibility of her serving as U.S. Secretary of State in his administration. Clinton initially turned Obama down, but he persisted. When the possibility became public on November 14, it came as a surprising and dramatic move, especially given the long, sometimes bitter battle the two had waged during the 2008 Democratic Party presidential primaries. Obama had specifically criticized Clinton's foreign policy credentials during the contests, and the initial idea of him appointing her had been so unexpected that she had told one of her own aides, "Not in a million years." However, Obama had been thinking of the idea as far back as the 2008 Democratic National Convention.Wolffe, Renegade, p. 313. Despite the aggressiveness of the campaign and the still-lingering animosities between the two campaign staffs, as with many primary battles, the political differences between the candidates were never that great,Libert and Faulk, Barack, Inc., pp. 133–134. the two rivals had reportedly developed a respect for one another, and she had campaigned for him in the general election. Consideration of Clinton was seen as Obama wanting to assemble a "team of rivals" in his administration, as had Abraham Lincoln.

Clinton was conflicted whether she wanted to take the position or remain in the Senate, and agonized over her decision. While the Senate leadership had discussed possible leadership positions or other promotions in rank with her even before the cabinet position became a possibility, nothing concrete had been offered. The prospect of her ever becoming Senate Majority Leader seemed dim.Wolffe, Renegade, p. 314. A different complication was her husband's role. She told Obama: "it will be a circus if I take this job", making reference to the volatile effect Bill had during the primaries. In addition, there was a specific concern whether the financial and other involvements of Bill Clinton's post-presidential activities would violate any conflict-of-interest rules for serving cabinet members. There was as well considerable media speculation about what effect taking the position would have on her political career and any possible future presidential aspirations. Clinton wavered over the offer, but as she later related, "But, you know, we kept talking. I finally began thinking, look, if I had won and I had called him, I would have wanted him to say yes. And, you know, I'm pretty old-fashioned, and it's just who I am. So at the end of the day, when your president asks you to serve, you say yes, if you can." Clinton said she was reluctant to leave the Senate, but that the new position represented a "difficult and exciting adventure". As part of the nomination, Bill Clinton agreed to accept a number of conditions and restrictions regarding his ongoing activities and fundraising efforts for the Clinton Presidential Center and Clinton Global Initiative.

The appointment required a Saxbe fix, which was passed and signed into law in December 2008 before confirmation hearings began. Confirmation hearings before the Senate Foreign Relations Committee began on January 13, 2009, a week before the Obama inauguration. Clinton stated during her confirmation hearings that she believed that "the best way to advance America's interests in reducing global threats and seizing global opportunities is to design and implement global solutions" and "We must use what has been called 'smart power', the full range of tools at our disposal—diplomatic, economic, military, political, legal and cultural—picking the right tool or combination of tools for each situation. With smart power, diplomacy will be the vanguard of our foreign policy."

On January 15, the Committee voted 16–1 to approve Clinton. ; . Republican Senator David Vitter of Louisiana was the lone dissenting vote in the committee. By this time, Clinton's public favorable/unfavorable rating had reached 65 percent, the highest point in her public career since the Clinton–Lewinsky scandal during her time as First Lady, and 71 percent of the public approved of the nomination to the cabinet.

Even before taking office, Clinton was working together with Bush administration officials in assessing national security issues. The night before the inauguration of the new president, contingency plans against a purported plot by Somali extremists against Obama and the inauguration was being discussed. Clinton argued that typical security responses were not tenable: "Is the Secret Service going to whisk him off the podium so the American people see their incoming president disappear in the middle of the inaugural address? I don't think so." (The threat turned out to not exist.) On January 21, 2009, Clinton was confirmed in the full Senate by a vote of 94–2. Vitter and Republican Senator Jim DeMint of South Carolina voted against the confirmation.

Clinton took the oath of office of Secretary of State that same day. Just before being sworn in as Secretary of State, Clinton resigned her Senate seat effective just hours before her oath as Secretary of State. She became the first former First Lady to serve in the United States Cabinet. She also became the first Secretary of State to have previously been an elected official since Edmund Muskie's less-than-a-year stint in 1980, with Christian Herter during the Eisenhower administration being the last one before that. In being selected by her formal rival Obama, she became only the fourth person in the preceding hundred years to join the cabinet of someone they had run against for their party's presidential nomination that election year (Jack Kemp ran against and was later chosen by George H. W. Bush to be Secretary of HUD in 1988, George W. Romney by Richard Nixon for Secretary of HUD in 1968, and Philander Knox by William Howard Taft for Secretary of State in 1908 preceded her; Obama's pick of Tom Vilsack for Secretary of Agriculture followed her a couple of weeks later to be the next such person).

(On January 29, 2009, the constitutionality of her Saxbe fix was challenged in court by Judicial Watch; on October 30, 2009, the courts dismissed the case.)

Staff During the presidential transition, Clinton's former campaign manager, Maggie Williams, handled the staff hiring process. Longtime counsel to both Clintons Cheryl Mills served as the secretary's Counselor and Chief of Staff. James B. Steinberg was named Deputy Secretary of State. Jacob "Jack" Lew, once Bill Clinton's Director of the Office of Management and Budget, was named Deputy Secretary of State for Management and Resources, a new position. This was an unusual step intended by Hillary Clinton to push to the forefront the emphasis on getting higher budget allocations from Congress and overlooking internal workings. Anne-Marie Slaughter was appointed Director of Policy Planning with a view towards long-term policy towards Asia. Huma Abedin, Clinton's longtime personal assistant, was Deputy Chief of Staff for the secretary and remained a key member of Clinton's operation.

Much like she did at the beginning of her Senate career, Clinton kept a low profile during her early months and worked hard to familiarize herself with the culture and institutional history of the department. She met or spoke with all of the living former secretaries, and especially relied upon her close friendship with Madeleine Albright.

At the start of her tenure, Obama and Clinton announced several high-profile special envoys to trouble spots in the world, including former Senate Majority Leader George Mitchell as Mideast envoy and Richard Holbrooke as envoy to South Asia and Afghanistan. Clinton appointed Todd Stern as the department's Special Envoy for Climate Change.

By May 2009, Clinton and the Obama administration intended to nominate Paul Farmer as administrator of the United States Agency for International Development (USAID), but by August his nomination was dead. This caused Clinton to publicly criticize the long vetting process for administration appointments/ In November, an unconventional choice was nominated instead, Rajiv Shah, a young Under Secretary of Agriculture for Research, Education, and Economics. Clinton said, "He has a record of delivering results in both the private and public sectors, forging partnerships around the world, especially in Africa and Asia, and developing innovative solutions in global health, agriculture, and financial services for the poor."

Despite some early press predictions, in general Clinton's departmental staff has avoided the kind of leaks and infighting that troubled her 2008 presidential campaign. One possibly lingering line of internal tension was resolved in early 2011 when State Department spokesperson P. J. Crowley resigned after making personal comments about in-captivity leaker Chelsea Manning and her treatment by the Department of Defense. In other changes, Jacob Lew left in late 2010 to join the White House as Office of Management and Budget and was replaced as Deputy Secretary of State for Management and Resources by Thomas R. Nides (Lew would eventually become White House Chief of Staff and then the pick for U.S. Treasury Secretary for Obama's second term), and Steinberg left in mid-2011 and was replaced as Deputy Secretary by career diplomat William J. Burns.

Early themes and structural initiatives During the transition period, Clinton sought to build a more powerful State Department. She began a push for a larger international affairs budget and an expanded role in global economic issues. She cited the need for an increased U.S. diplomatic presence, especially in Iraq where the U.S. Defense Department had conducted diplomatic missions. U.S. Secretary of Defense Robert Gates agreed with her, and also advocated larger State Department budgets. Indeed, the two, and their respective departments, would have a productive relationship, unlike the often fraught relations between State and Defense and their secretaries seen in prior administrations.