James Chace, an influential historian and foreign policy analyst whose work was shaped by his youthful experiences in France and was known for its literary grace, died Oct. 8 of a heart attack at 72. He was in Paris, where he was conducting research on what would have been his 10th book, a biography of the Marquis de Lafayette. He lived in New York.

Mr. Chace became a leading foreign policy analyst without rising through the customary apprenticeships. He did not work in government, and he was not, at least until his later years, an academic. He often wrote for newspaper op-ed pages and was a longtime contributor to the New York Review of Books, but he was not a journalist in the ordinary sense.

Instead, he found a position of influence through his own writing and by editing foreign policy journals, most visibly as managing editor of Foreign Affairs and as editor of World Policy Journal. His 1998 biography of Dean Acheson, secretary of state from 1949 to 1953, was considered a landmark for its lucid descriptions of Acheson's personality and the policies that have guided U.S. diplomacy for the past half-century.

Mr. Chace's other books examined the economics of foreign policy, American isolationism, post-communist Europe and U.S. involvement in Central America. His most recent book, published in May, explored the drama and long-range effects of the U.S. presidential election of 1912. He also wrote an affecting memoir, "What We Had," about his shabby-genteel childhood in a family of fallen Massachusetts aristocrats.

"He was motivated by a powerful sense of history," said a longtime friend, author Ronald Steel. "He believed political decisions aren't made by mathematical formulations, but by people with personalities, foibles and problems. That sense of the importance of personality infused his writing and allowed him to go beyond the narrow interpretations of policy wonks."

Mr. Chace never held a position in the government, yet a conversation he had with Clinton White House adviser Sidney Blumenthal led to a phrase made famous by then-Secretary of State Madeleine Albright, in which she called the United States the "indispensable nation" in a fractured age in which it was the world's sole superpower.

Mr. Chace also believed that the United States needed to form partnerships with other nations and could not afford, either financially or morally, to isolate itself from the rest of the world. In a commentary written this year for the Los Angeles Times, he described what he termed the "Bush doctrine" and the preemptive invasion of Iraq as a "fundamental departure from American traditions."

The idea of launching attacks against foreign foes dates back nearly 200 years, he wrote, but had almost always been rejected by U.S. leaders. The risk, Mr. Chace contended, was that "even our sometime allies would view the United States as a pariah nation -- to be feared, to be isolated, to be contained."

Mr. Chace was born in Fall River, Mass., on Oct. 16, 1931. His paternal grandfather had been president of the Massachusetts State Senate, and his mother's family had owned some of the land on which New York's Central Park was built. But after the collapse of Fall River's cotton-mill economy, his family fell into debt. In his memoir, Mr. Chace said dinner-table conversations inevitably led back to the same question: "What happened to the money?"

He graduated from Harvard, where he studied literature, French and Italian and took only a single course in history. After college, he went to France to study the painter Eugene Delacroix and the writer Charles Baudelaire but found himself caught up in the heady intellectual swirl of literature and politics.

"To go to Paris in 1954 as a student and remain indifferent to politics," he wrote in an essay for The Washington Post's Book World on Aug. 15, "would have been as impossible as for a young French student to come to America in 1968 . . . and remain in an ivory tower of self-involvement."

As an Army translator in France in 1955 and 1956, he watched the French retreat from Vietnam and the problems of its rebellious colony in Algeria. He worked at Esquire magazine for two years and wrote a novel while in his twenties. But he grew increasingly interested in foreign policy, working at two magazines, East Europe and Interplay, before joining Foreign Affairs, where he was managing editor from 1970 to 1983. He was known as a superb editor with a gift for language.

He worked at the New York Times Book Review in the 1980s and, from 1992 to 2000, as editor of World Policy Journal. He was a senior associate of the Carnegie Endowment for International Peace in Washington from 1997 to 1999. Since 1990, he had been a professor of government and public law and administration at Bard College in Annandale-on-Hudson, N.Y. In 1986, he was awarded a Chevalier des Arts et Lettres from the French government.

"He was a person of unsurpassed charm," said Blumenthal, a friend for 20 years. "He had an enormous capacity for friendship and was a mentor to many younger people."

Mr. Chace was twice married to the poet Jean Valentine and twice divorced. His marriage to Susan Denvir also ended in divorce.

Survivors include his companion, Joan Bingham of Washington and New York; three daughters; and two grandchildren.

In his essay for Book World, Mr. Chace wrote: "None of us can escape the consequences -- both good and ill -- of the exercise of American power on a global scale or the personal and private decisions made by public figures that will affect the shape of the world to come."

James Chace's works included a biography of Dean Acheson and a history of U.S. isolationism.