And in 2003, his was the first criticism to stick against the case for the second U.S. invasion of Iraq. Days after Wilson said he'd investigated and largely discounted the notion that Iraq tried to buy uranium from Niger, the White House retracted the allegation.
Now Wilson, 53, is the central figure in a high stakes dispute over who leaked his wife's name, and her apparent work for the CIA, to the press, and whether that leak broke federal law barring the identification of clandestine agents.
It's a strange return to the spotlight for a man who quietly rose through the Foreign Service ranks prior to the first Gulf War, and has largely avoided the headlines after it.
Wilson was born in Bridgeport, Conn., and went to college at the University of California at Santa Barbara.
Fluent in French, he joined the Foreign Service in 1976 and did tours in Niger, Togo and South Africa, according to the Middle East Institute. In 1982, he was made deputy chief of mission in Burundi's capital Bujumbura.
From 1985 to 1986, as a fellow with the American Political Science Association, he worked in the offices of then Sen. Al Gore and former House Speaker Tom Foley, who was a majority whip at the time.
Wilson then returned to Africa as deputy chief of mission in Brazzaville, capital of the Republic of Congo, for two years.
It was his next assignment that first gave Wilson a small place in the history books. From 1998 to 1991, he served as deputy chief of the U.S. mission in Baghdad.
He was thrust into the role of acting ambassador when Iraq invaded Kuwait because April Glaspie, the actual ambassador, was out of the country at the time of the invasion.
During the long build-up to the Gulf war, Wilson "had almost daily shouting matches with his Iraqi counterparts," according to the Los Angeles Times. When the Iraqi Foreign Ministry posted a note threatening execution to diplomats who gave shelter to Western men who Saddam claimed were hostages, Wilson called the Ministry to ask if they intended to hang him. The Iraqi threat was retracted.
Eventually, Wilson was credited with negotiating the release of several hundred American hostages.
After leaving his post in Baghdad, Wilson was Ambassador to Gabon and to Sao Tome and Principe from 1992 to 1995. For the next two years, he served as the political adviser to the Commander-in-Chief of United States Armed Forces in Europe.
He was appointed to the National Security Council in 1997, and handled African affairs there. He left the council in 1998.
Wilson, a father of two, now runs J.C. Wilson International Ventures. In an online chat with The Washington Post, he said the company does " political risk assessment for companies wanting to do business in Africa Europe and the Middle East."
Some Republicans have said Wilson has a partisan agenda to embarrass President Bush. Wilson admits to the Post to being a left-leaning Democrat, but friends told the paper he did not have an axe to grind.
The Federal Election Commission indicate Wilson have donated $5,250 to campaigns since 1997. Gore's presidential campaign received $3,000. A Republican congressional candidate received $1,000.
Prior to this year's invasion of Iraq, Wilson sounded a cautionary tone. He predicted Saddam would try to "drive a wedge" between the United States and its allies, and warned that asking Iraq to disarm itself was futile.
"Disarmament is a wonderful goal, but the Iraqis didn't build their weapons of mass destruction because they hate America," he told the Times. "They built them because they are in a tough neighborhood. They built them because they are afraid of three strong countries nearby: Israel, Turkey and Iran."
Wilson also foresaw a "nasty" postwar environment.
"This isn't going to be like the invasion of Grenada or the revolution in Portugal, where you had people sticking flowers in the guns of soldiers," Wilson said in remarks quoted by the St. Louis Post-Dispatch. "The more likely outcome is going to be a very, very nasty affair, with Shiite and Kurdish factions grabbing for power, reprisals against Sunni Muslim followers of Saddam and, in the middle, a U.S. army of occupation."