WASHINGTON — Richard Holbrooke, a brilliant and feisty U.S. diplomat who wrote part of the Pentagon Papers, was the architect of the 1995 Bosnia peace plan and served as President Obama’s special envoy to Pakistan and Afghanistan, died Monday, an administration official said. He was 69.

Holbrooke, whose forceful style earned him nicknames such as “The Bulldozer” and “Raging Bull,” was admitted to the hospital on Friday after becoming ill at the State Department. The former U.S. ambassador to the U.N. had surgery Saturday to repair a tear in his aorta, the body’s principal artery.

Earlier Monday, Obama praised Holbrooke for making America safer.

“He is simply one of the giants of American foreign policy,” Obama said during a holiday reception at the State Department.

Secretary of State Hillary Clinton also hailed Holbrooke’s long service.

“He has given nearly 50 years of his life to serving the United States,” Clinton said Monday during a meeting in Canada.

Holbrooke served under every Democratic president from John F. Kennedy to Obama in a lengthy career that began with a foreign service posting in Vietnam in 1962 after graduating from Brown University, and included time as a member of the U.S. delegation to the Paris Peace Talks on Vietnam.

His sizable ego, tenacity and willingness to push hard for diplomatic results won him both admiration and animosity.

“If Richard calls you and asks you for something, just say yes,” former Secretary of State Henry Kissinger once said.

“If you say no, you’ll eventually get to yes, but the journey will be very painful.”

He learned to become extremely informed about whatever country he was in, push for an exit strategy and look for ways to get those who live in a country to take increasing responsibility for their own security.

“He’s a bulldog for the globe,” Tim Wirth, president of the United Nations Foundation, once said.

Born in New York City on April 24, 1941, Richard Charles Albert Holbrooke had an interest in public service from his early years.

He was good friends in high school with a son of Dean Rusk and grew close to the family of the man who would become a secretary of state for presidents Kennedy and Johnson.

Holbrooke was a young provincial representative for the U.S. Agency for International Development in South Vietnam and then an aide to two U.S. ambassadors in Saigon. At the Johnson White House, he wrote one volume of the Pentagon Papers, an internal government study of U.S. involvement in Vietnam that was completed in 1967.

The study, leaked in 1971 by a former Defense Department aide, had many damaging revelations, including a memo that stated the reason for fighting in Vietnam was based far more on preserving U.S. prestige than preventing communism or helping the Vietnamese.

A lifelong Democrat, he returned to public service when Bill Clinton took the White House in 1993.

One of his signature achievements was brokering the Dayton Peace Accords that ended the war in Bosnia. He detailed the experience of negotiating the deal at an Air Force base near the Ohio city in his 1998 memoir, “To End a War.”

James Dobbins, former U.S. envoy to Afghanistan who worked closely with Holbrooke early in their careers, called him a brilliant diplomat and said his success at the Dayton peace talks “was the turning point in the Clinton administration’s foreign policy.”