The Project for the New American Century (PNAC) was a prominent neoconservative think tank and advocacy group, now defunct, founded in 1997 by William Kristol and Robert Kagan as a non-profit educational organization based in Washington, D.C. Operating until 2006, it advocated for American global leadership through military strength, emphasizing a robust foreign policy grounded in military dominance, moral clarity, and interventionism inspired by Reagan-era principles. PNAC sought to build public and political support for increased defense spending, maintaining U.S. military superiority, and proactive engagement in international affairs to shape a favorable global order. The organization promoted regime change policies, including the removal of Saddam Hussein from power in Iraq, as reflected in its 1998 letter to President Clinton urging Saddam's removal—a letter signed by many future Bush administration officials.

PNAC gained significant influence during the late 1990s and early 2000s through policy papers and open letters to U.S. presidents. Zalmay Khalilzad was a charter signatory of its 1997 founding statement of principles and signed the 1998 letter. The group had strong ties to the American Enterprise Institute and was associated with key figures such as Dick Cheney, Donald Rumsfeld, and Paul Wolfowitz, who later served in the George W. Bush administration. Its 2000 report, "Rebuilding America's Defenses," called for a transformative U.S. military posture, including regime change in Iraq, and notably referenced the need for a "new Pearl Harbor" event to catalyze public support.

PNAC's ideas played an instrumental role in shaping the intellectual rationale for the 2003 Iraq War, advocating for the removal of Saddam Hussein and the spread of democracy in the Middle East. The organization ceased operations in 2006, winding down after the initial phases of the Iraq War. Its legacy remains controversial—praised by supporters for advancing U.S. strategic interests but criticized by opponents for encouraging aggressive unilateralism and contributing to prolonged conflicts. PNAC's influence persists through alumni networks and the continued evolution of neoconservative thought in American policy circles.