Walter Haskell Pincus (born December 24, 1932) is a national security journalist for The Washington Post. He has won several prizes including a Polk Award in 1977, a television Emmy in 1981, the 2002 Pulitzer Prize for National Reporting in association with other Washington Post reporters, and the 2010 Arthur Ross Media Award from the American Academy for Diplomacy. Since 2003, he has taught at Stanford University's Stanford in Washington program.
In October 2003, Pincus cowrote a story for the Washington Post which described a July 12, 2003 conversation between an unnamed administration official and an unnamed Washington Post reporter. The official told the reporter that Iraq war critic Joe Wilson's wife Valerie Plame worked for the Central Intelligence Agency's (CIA) nonproliferation division, and suggested that Plame had recommended her husband to investigate reports that Iraq's government had tried to buy uranium in Niger. It later became clear that Pincus himself was the Post reporter in question. Special Counsel Patrick Fitzgerald issued a grand jury subpoena to Pincus on August 9, 2004, in an attempt to discover the identity of Pincus' secret informant. On August 20, 2004, the Post filed a motion to quash the subpoena, but after Pincus' source came forward to speak with investigators, Pincus gave a deposition to Fitzgerald on September 15, 2004; he recounted the 2003 conversation to Fitzgerald but still did not name the administration official. In a public statement afterward, Pincus said that the special prosecutor had dropped his demand that Pincus reveal his source. On February 12, 2007, Pincus testified in court that it was then White House Press Secretary Ari Fleischer, swerving off topic during an interview, who had told him of Plame's identity. Pincus was interviewed about his involvement in the Plame affair, and his refusal to identify his source, in the first episode of Frontline's "News War".