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. He is the author of The Strategy of Denial: American Defense in an Age of Great Power Conflict (Yale University Press), which The Wall Street Journal selected as one of the top ten books of 2021. 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). The NDS shifted the Department of Defense’s focus to the challenges to U.S. military superiority and interests posed by China in particular followed by Russia, prioritizing restoring the Joint Force’s warfighting edge against these major power competitors. He also served as the primary Defense Department representative in the development of the 2017 National Security Strategy.