In January 2003 John Brady Kiesling, political counselor at the US Embassy in Greece, hosted a dinner party for a dozen European artists and intellectuals at his apartment in Athens. Most of the guests were friendly to the United States, but none of them could fathom the Bush Administration’s inexorable march to war in Iraq. As a career diplomat obligated to defend his country’s foreign policy, Kiesling reflexively counterattacked with prowar arguments, but the rhetorical effort left him exhausted and irritable. “At the end of the evening,” he later explained, “I realized how threadbare and unconvincing my arguments had been. And these were people who like Americans!”

A few weeks later Kiesling resigned from the State Department. “Our fervent pursuit of war with Iraq,” he wrote in an eloquent letter to Secretary of State Colin Powell, “is driving us to squander the international legitimacy that has been America’s most potent weapon of both offense and defense since the days of Woodrow Wilson.” That letter turned Kiesling into an antiwar celebrity and brought him an admiring handwritten note from Bill Clinton.

“My personality,” Kiesling says with a wan smile, “is not really that suited to going out and being a rock star.” That’s true: He has none of the swagger and charisma we tend to associate with whistleblowers and mavericks like Daniel Ellsberg and Joseph Wilson. With his light blue button-down shirt, khaki pants, black loafers and round glasses, Kiesling, youthful at 49, carries himself like an assistant professor of English or an earnest young librarian. One senses a steeliness in him, but also a sense of fragility. Did he make the correct decision to terminate his twenty-year career in the foreign service? “Yes, I’m much happier now,” he responds without hesitation. “Everyone has to punch some ticket in life that says they have made a difference.”

Kiesling was recently in New York City to promote his new book, Diplomacy Lessons, and I met him at an apartment across from Washington Square Park, where he was staying with an old friend. Diplomacy Lessons is three things: an autopsy of the Bush Administration’s foreign policy by a man whose job was to help implement it; a primer on the art (and necessity) of first-rate diplomacy in an era of unilateral gunslinging; and a memoir of Kiesling’s years as a foreign service officer in Israel, Armenia, Morocco and Greece, the country he loves the most and the place he now calls home. The pages devoted to Kiesling’s career are among the most gripping in the book.

In those pages, we see an idealistic young man, with a newly minted graduate degree from Berkeley in Mediterranean archeology and ancient history, who took the foreign service exam in 1983. We see a hapless diplomat in Morocco who, with the best of intentions, once tried to broker a deal between a restless neighbor (a proud, impoverished Islamic university student) and a US intelligence officer, a deal that quickly collapsed. We see him gaining confidence as a junior diplomat: schmoozing with power brokers and literati, scanning the Greek press for political minutiae and making the long drive every few months to the headquarters of the Communist Party of Greece, where, near a huge bust of Lenin, he would spend an hour arguing with the Politburo member in charge of international relations.

And finally we witness his growing disillusionment with US diplomacy after 9/11 and the ways those sentiments expanded his political consciousness and drove him to despair. Strolling through the old quarter of Ankara in the weeks after the US assault on Falluja, Kiesling saw signs in tourist shops that read “Americans Not Welcome.” In light of these and other incidents, some old shibboleths in his mind began to crumble. In 2001 he smugly assured the publisher of a left-wing newspaper in Athens that Noam Chomsky was “clinically insane.” Writes Kiesling in his new book, “I feel more charitably disposed toward Chomsky now.”

It wasn’t principle alone that inspired Kiesling’s act of rebellion. Diplomacy Lessons chronicles the administrative and bureaucratic imbroglios that preceded his decision to resign. It’s a tangled and psychologically complex story. In 2002 Kiesling ran into difficulty with the diplomatic security division of the Embassy in Athens, which routinely sends young Marines to offices after hours in search of unsecured classified material. If an unsecured document is located, a pink slip is deposited. Kiesling’s pink slips began to proliferate, and he was informed that he was ineligible for promotion for one year. “Almost certainly,” he writes, “the lapses were my fault, the result of working too late with too little sleep.” But he also felt he was being punished arbitrarily. “Every political officer who actually does any work runs afoul of this system once or twice,” he says now. When he sought the support of his Ambassador, Thomas Miller, and was rebuffed, Kiesling felt he no longer had “absolute faith in the integrity of the system I worked for.” His anger toward Miller, combined with the queasiness he felt about the imminent war in Iraq, gave him the courage to resign, he says.

Doing so meant sacrificing a steady career. With his savings depleted, he is scrambling to build a new life for himself, writing for an English-language Athens newspaper and researching a book about the November 17 organization–a “little tiny terrorist group,” he relates, “that for twenty-five years tied the US government in knots in Greece.” Eventually he would like to support himself as a freelance writer in Greece, where he says the cost of living is less than in the United States and where he appears to be held in high esteem, but his anxiety about the future is palpable.

Kiesling may have lost faith in the Bush-era State Department, but he remains idealistic about the diplomatic profession. His book is dedicated to “the new generation of the US Foreign Service, whose faith in their country and curiosity about the planet will bring new pride to a proud profession.” Already he’s in contact with that new generation. “I recruited a couple of potential new foreign service officers on my book tour these last few days,” explains Kiesling. “A really bright guy working on War News Radio at Swarthmore College now says he wants to take the foreign service exam and he e-mailed me on how to do it.”