Henry Kissinger, one of the most influential and controversial diplomats of the 20th century, died Wednesday at age 100, his firm said. 

Kissinger, who served as secretary of state and national security adviser under Presidents Richard Nixon and Gerald Ford, remained a prominent voice on foreign policy issues long after leaving government in 1977. 

"I work about 15 hours a day," he told CBS News weeks before he turned 100, saying with confidence that world leaders like China's Xi Jinping or Russia's Vladimir Putin would likely take his calls.  

He was known for his practice of "realpolitik" — engaging with the world based on practical objectives rather than moral ideals — and was credited with the secret diplomacy that helped thaw U.S. relations with China. But he was also accused of alleged war crimes for the bombing of Cambodia during the Vietnam War, backing Pakistan's genocide in Bangladesh, and green-lighting the Argentine dictatorship's "dirty war" against dissidents. 

He was born in Germany on May 27, 1923, as Heinz Alfred Kissinger. Less than three months before Kristallnacht, in 1938, his Jewish family fled Nazi Germany and resettled in New York City, where he became known as Henry. 

After his first year at George Washington High School, he took night classes and worked in a shaving brush factory during the day, according to "Kissinger: A Biography" by Walter Isaacson. After graduating, he enrolled in the City College of New York and planned to become an accountant. But he was drafted into the U.S. Army shortly after his 19th birthday. 

Kissinger, who became a naturalized U.S. citizen in 1943, returned to his motherland as a German interpreter in the U.S. Army. He also arrested Gestapo members and helped liberate prisoners from the Ahlem concentration camp. 

"I had not realized until I saw the camp, the depths to which human beings could be reduced," he told the BBC in an interview that aired in July 2022. 

He was awarded the Bronze Star for his time in the Army's counterintelligence unit developing informants that led to the Gestapo arrests. 

Upon his return to the U.S. after the war, he enrolled at Harvard, where his senior thesis on "the meaning of history" became legend, according to Isaacson's biography. At nearly 400 pages, it was longer than any previous undergraduate thesis and reportedly brought about the "Kissinger rule" that limited the length of future students' theses. 

In the following years, Kissinger completed his doctorate at Harvard and joined the faculty. In 1957, he was named the associate director of Harvard's Department of Government and Center for International Affairs. He was also a consultant to several government agencies, including the State Department. 

In 1968, Nixon chose Kissinger to be his national security adviser and during his second term appointed him as secretary of state. Kissinger was the first to serve in both roles at the same time, and he retained both titles in the Ford administration after Nixon resigned. 

Kissinger's outreach to the Soviet Union and China is widely viewed as reshaping the direction of the Cold War. He negotiated the Strategic Arms Limitation Talks and the Anti-Ballistic Missile Treaty with the USSR, lowering tensions between the two nuclear superpowers. And he opened backchannel talks between the U.S. and China in the early 1970s, leading to the establishment of formal diplomatic relations and Nixon's historic visit to China in 1972. 

His "shuttle diplomacy" also helped contain the 1973 Arab-Israeli war. 

But his influence on other conflicts around the globe has been more controversial. 

Kissinger played a key role in the U.S. carpet-bombing Cambodia during the Vietnam War, which killed thousands of civilians and helped enable the rise of the genocidal Khmer Rouge regime. Yet he also shared a Nobel Peace Prize in 1973 for his involvement in talks aimed at ending the Vietnam War.

Kissinger drew fierce criticism for other positions he deemed to be in American interests, including undermining a democratically elected government in Chile, which lay the groundwork for a military coup, and sending weapons to Pakistan's dictator, whose regime slaughtered residents of what's now Bangladesh. In 1976, when right-wing military leaders seized power in Argentina, Kissinger told them, "If there are things that have to be done, you should do them quickly." Human rights abuses were rampant; tens of thousands of people were tortured, assassinated or "disappeared."

"That's a reflection of their ignorance," Kissinger told CBS News in response to those who saw him as a war criminal. "It wasn't conceived that way. It wasn't conducted that way."

After leaving government in 1977, Kissinger remained a prominent presence in foreign policy circles for decades. Even into his late 90s, he continued publicly weighing in on global events, consulting for business clients and privately advising American presidents.

"I've had the honor that I have been able to do sometimes little, and sometimes more important, things for 10 presidents, starting with Kennedy," Kissinger said in a 2012 interview with CBS News. "I had a very friendly relationship with Bush 43. He invited me quite frequently to talk with him."

More recently, he shared foreign policy advice with then-President Trump, who praised Kissinger's "immense talent" at a White House meeting in 2017. 

If a president were to ask him to talk with Putin amid the war in Ukraine, Kissinger, on the cusp of 100 years old, said he'd "be inclined to do it." 

"On behalf of our family, and of all those who worked with our father and Dr. Henry A. Kissinger in a partnership that produced a generation of peace for our nation, we express our deepest condolences on the passing of one of America's most skilled diplomats," Nixon's daughters, Tricia Nixon and Julie Nixon Eisenhower, said in a statement.

Former President George W. Bush said in a statement Wednesday, "America has lost one of the most dependable and distinctive voices on foreign affairs."

"He worked in the Administrations of two Presidents and counseled many more," Bush wrote. "I am grateful for that service and advice, but I am most grateful for his friendship. Laura and I will miss his wisdom, his charm, and his humor. And we will always be thankful for the contributions of Henry Kissinger."

Kissinger is survived by his two children, Elizabeth and David, from his first marriage, as well as his wife, Nancy, whom he married in 1974.

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• Henry Kissinger
• Obituary

Caitlin Yilek

Caitlin Yilek is a politics reporter at cbsnews.com and is based in Washington, D.C. She previously worked for the Washington Examiner and The Hill, and was a member of the 2022 Paul Miller Washington Reporting Fellowship with the National Press Foundation.

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