Elbridge Colby is co-founder and principal of The Marathon Initiative, a policy initiative focused on developing strategies to prepare the United States for an era of sustained great power competition. Previously, Colby was from 2018-2019 the director of the Defense Program at the Center for a New American Security, where he led the Center’s work on defense issues. Before that, he served as the deputy assistant secretary of defense for Strategy and Force Development from 2017-2018. In that role, he served as the lead official in the development and rollout of the Department’s preeminent strategic planning guidance, the 2018 National Defense Strategy (NDS). He also served as the primary Defense Department representative in the development of the 2017 National Security Strategy. A member of the Council on Foreign Relations and the International Institute of Strategic Studies, Colby is a graduate of Harvard College and Yale Law School.