In 1983, William H. Luers, a new American ambassador to Czechoslovakia, bet on a long shot for its future: Vaclav Havel, the often-imprisoned poet-playwright and enemy of the Communist state. But after leading a peaceful revolution to oust the regime, the long shot cultural leader became the democratically-elected last president of Czechoslovakia and the first president of its successor, the Czech Republic.

The ambassador’s contribution to Mr. Havel’s very survival in the last years of Communist rule, and his subsequent political successes were, in his own telling, results of maneuvers as gentle as the so-called Velvet Revolution that extricated Czechoslovakia from the Communists in 1989.

To spare Mr. Havel from an assassin’s bullet, a poison pill or a return to prison — where he might have been snuffed out quietly — Mr. Luers enlisted dozens of American cultural celebrities, mostly friends of his, to visit Prague, meet the playwright and then, at news conferences outside the reach of the government-controlled Czech news media, recast him in a protective armor of global publicity.

“I spent a lot of my career with artists and writers, promoting the arts,” Mr. Luers said in a 2022 interview for this obituary. “I was worried that the Communists might poison him or put him back in prison. My strategy was to shine as much light on Havel as possible. So I brought in John Updike, Edward Albee and many other people to talk about how great an artist and cultural leader he was.”

The recruited celebrities, Mr. Luers said, included the novelists E.L. Doctorow, Kurt Vonnegut and William Styron; Philippe de Montebello, the director of New York’s Metropolitan Museum of Art; Joseph Papp, the producer-director who created Shakespeare in the Park; the California abstract painter Richard Diebenkorn; and Katharine Graham, the publisher of The Washington Post.

The secret police filmed and photographed the visitors, but they were hardly people who could be intimidated. Indeed, Mr. Luers said, it was ultimately the Communist authorities who were cowed by the worldwide attention accorded to Mr. Havel. The underlying message, he said, was that harming Mr. Havel might risk incalculable international consequences for the Czech government.