Tom Greenwood works as a Research Staff Member at the Institute for Defense Analyses (IDA) in Alexandria, Virginia. His area of focus is strategy, defense policy, and joint warfare. He served 31 years in the U.S. Marine Corps as an infantry officer where he conducted peacekeeping and humanitarian assistance operations (Philippines, Haiti, Sierra Leone, Indonesia, and Sri Lanka) and counterinsurgency operations in Iraq. Before retiring in 2008, he commanded the 15th Marine Expeditionary Unit and served as the Director of the Marine Corps Command and Staff College. From 2011-2015, he was Director of the Pakistan desk in the Office of the Secretary of Defense for Policy. He served on the National Security Council staff at the White House under Presidents Clinton, G. W. Bush, and Barack Obama where he worked on a diverse array of policy issues that included the Balkans, Afghanistan, Iraq, foresight, and drafting of National Security Strategy documents.