To survey the triumphs and disappointments of post-World War II American history is to marvel at their entwinement with the biography of Colin Luther Powell, who died Monday at 84. The career of this remarkable soldier-statesman, the first Black person to serve as chairman of the Joint Chiefs of Staff, national security adviser and secretary of state, and the only person — period — to have served as all three, would have been unimaginable but for the greatest triumph of his era, the civil rights revolution. Yet Mr. Powell began his rise in a nearly all-White Army officer corps by serving in the disaster known as the Vietnam War.

His personal and professional outlook shaped in that crucible, Mr. Powell, as an increasingly influential adviser to Republican Cabinet officers and presidents, went on to help shape history himself: the United States’ triumph over the Soviet Union in the Cold War; the American victory in the 1991 Gulf War; the U.S. response to the Sept. 11, 2001, terrorist attacks, including the invasions of Iraq and Afghanistan.

This necessarily partial list barely does justice to Mr. Powell’s full impact on the country, which reached a kind of peak with the Powell-for-president boom in the mid-1990s. He demurred, but not before the phenomenon inspired many Americans, of all races, to take more seriously the possibility that Americans would elect a president of color. When that did happen in 2008, Mr. Powell played a part — breaking Republican ranks to endorse Democrat Barack Obama.

Mr. Powell left his imprint on popular culture with his “Pottery Barn rule,” first used in a 2002 meeting with then-President George W. Bush (and later leaked), regarding the risks Mr. Bush assumed by invading Iraq: “You break it, you own it.” The phrase, with its dovish implications, reflected Mr. Powell’s instincts. Having emerged from Vietnam and decided to remain in the Army — while many other young officers left — Mr. Powell devoted himself to rebuilding and restoring what had become, by the late 1970s, a deeply troubled institution. He vowed that he and fellow Army officers would prevent another Vietnam by "not quietly acquiesc[ing] in halfhearted warfare for half-baked reasons that the American people could not understand,” as he put it. He helped the Pentagon not only restore training and discipline but also develop demanding criteria for the use of force: clear, attainable objectives; public and international support; a plausible exit strategy.

The “Powell Doctrine” pressured civilian policymakers to think long and hard before putting troops in harm’s way. Critics saw it as an elaborate rationalization for inaction. At times during Mr. Powell’s chairmanship of the joint chiefs between 1989 and 1993, it was, as when the United States hesitated to stop “ethnic cleansing” of Bosnia’s Muslims. Yet successful military operations in the same period — the Gulf War, the 1989 invasion of Panama — benefited from Mr. Powell’s insistence that their costs and benefits be thoroughly weighed and that, when used, force should be deployed swiftly and overwhelmingly.

Mr. Powell lost internal George W. Bush administration arguments over whether to invade Iraq. Then — ever the team player — he agreed to lend his credibility to claims that war was necessary because Saddam Hussein had weapons of mass destruction. He laid out the intelligence to the U.N. Security Council, but it was faulty; no chemical or biological weapons were found. Mr. Powell was left to absorb blame for a war that eventually went sour — as he had privately warned. This bitter experience left what he later called a “blot” on his record, which, with characteristic understatement, he described as “painful.”

Today there are those who would reduce Mr. Powell’s career to that mistake, or to others, such as his pushback in 1993 against efforts by a new president — Bill Clinton — to end the ban on gays serving openly in the military. This is myopic. Unlike some other powerful figures, Mr. Powell was capable, later, of taking responsibility and admitting his mistakes, which were outweighed by his accomplishments. And he never let the criticism dampen his generosity of spirit and determination to help others.

Mr. Powell’s favorite quotation, which he displayed on his desk at the Pentagon, was from the ancient Greek historian Thucydides: “Of all the manifestations of power, restraint impresses men most." Though the attribution may actually be apocryphal, one can understand why Mr. Powell embraced the sentiment. Experience — from the battlefield to the bureaucracy — had instilled a healthy suspicion of power untempered by character. Certainly Mr. Powell was true to himself, and to the values of his country, when, in recent years, he broke with the Republican Party and denounced the wanton figure, Donald Trump, who has taken it over.

In an interview with the New York Times in 2007, the old soldier spoke of himself in the third person, and in terms that, reading them today, define the missing ingredients of American politics: “Powell is a problem-solver. He was taught as a soldier to solve problems. So he has views, but he’s not an ideologue. He has passion, but he’s not a fanatic." Always aspiring to that balance of passion and wisdom, Colin Powell carved a special place in the nation’s history.