From 2006 to 2008, he also served as Deputy
Assistant Secretary of State for East Asian and Pacific Affairs. Christensen taught at
Cornell University,
Massachusetts Institute of Technology,
Princeton University, where he co-founded the China in the World program with Harvard professor
Alastair Ian Johnston in 2004. He was the William P. Boswell Professor of World Politics of Peace and War at Princeton University before joining the Columbia faculty in fall of 2018. He also sits on the faculty of the
Weatherhead East Asian Institute at Columbia. He has been described as a China expert by numerous Chinese and American publications.
Gideon Rose called his views on the international system as neorealist. Christensen served as a founding member of the Academic Advisory Council of the
Schwarzman Scholars program. He was also a silver medalist of the 2016
Arthur Ross Book Award from the
Council on Foreign Relations. In 2020, Christensen, along with over 130 other former Republican national security officials, signed a statement asserting that President
Donald Trump was unfit to serve another term, and "To that end, we are firmly convinced that it is in the best interest of our nation that Vice President Joe Biden be elected as the next President of the United States, and we will vote for him." He is a participant of the Task Force on U.S.-China Policy convened by the
Asia Society's Center on US-China Relations. == Publications ==