Smith worked for 25 years in a series of key reporting and editorial roles at The Washington Post, including national investigative editor, national security correspondent, national investigative correspondent, and a foreign staff bureau chief based in Rome. In 2006, he won the Pulitzer Prize for Investigative Reporting, along with two colleagues at the Post, for articles on House Majority Leader Tom DeLay and lobbyist Jack Abramoff. Smith was also a finalist with other Post reporters for the Pulitzer Prize in international reporting in 1999 (from Kosovo), and a finalist with others for the Pulitzer Prize in national reporting in 2005 (about Abu Ghraib and military prisoner abuse). In his first ten years at the Post, Smith wrote about defense, intelligence and foreign policy matters, including policymaking at the State Department, Pentagon, and White House. He also focused on conflict and terrorism in the Middle East; politics and military affairs in Asia; and arms proliferation. Prior to that, he was a senior writer for the News and Comment section of Science Magazine where he won a National Magazine Award in 1986 for writing about arms control.