American diplomat Joseph C. Wilson, who contradicted George W. Bush and one of his key reasons for entering the Iraq War, has died at his home in Santa Fe at the age of 69. Wilson, who served in many posts during his 23-year diplomatic career, famously undermined the Bush administration in an op-ed in The New York Times, after which his wife at the time, Valerie Plame, was outed as a C.I.A. agent, a reveal that resulted in allegations of political payback.

In 2002, Wilson was sent to Niger to verify reports that the country had sold uranium “yellowcake,” a nuclear material, to Iraq. At the time, Bush was building his case for invading Iraq on the presence of nuclear weapons. Wilson never found evidence that Iraq had obtained uranium, but in his 2003 State of the Union address, Bush said, “The British government has learned that Saddam Hussein recently sought significant quantities of uranium from Africa.” Wilson challenged that assertion in a New York Times op-ed titled, “What I Didn’t Find in Africa.” He wrote, “if, however, the information was ignored because it did not fit certain preconceptions about Iraq, then a legitimate argument can be made that we went to war under false pretenses.”