Menon is a senior research scholar at the Saltzman Institute of War and Peace Studies, Columbia University and a non-resident scholar at the Carnegie Endowment for International Peace. Menon has been a fellow at the Carnegie Council on Ethics in International Affairs and the New America Foundation, academic fellow at the Carnegie Corporation, research scholar at the Kennan Institute, Woodrow Wilson International Center for Scholars (the Wilson Center), and senior fellow at the Council on Foreign Relations. His books include Soviet Power and the Third World (Yale University Press, 1986), The End of Alliances (Oxford University Press, 2007), Conflict in Ukraine: The Unwinding of the Post-Cold War Order, coauthored with Eugene Rumer (MIT Press, 2015), and The Conceit of Humanitarian Intervention (Oxford University Press, 2016). His next book, Russia After Putin, co-authored with Eugene B. Rumer, is under contract to Oxford University Press.

In addition to publications in numerous academic journals, Menon has written for The New York Times, The Washington Post, Foreign Affairs, Financial Times, Los Angeles Times, The Boston Globe, The Guardian, Chicago Tribune, Boston Review, Foreign Policy, and The National Interest. He has appeared as a commentator on ABC, CNN, MSNBC, the BBC, NPR, France 24 Television, the Canadian Broadcasting Corporation, and Radio Australia. While an international affairs fellow of the Council on Foreign Relations from 1989–1990, Menon served as special assistant for national security (focusing on arms control) on the staff of the chair of the House Foreign Affairs Committee’s Asia-Pacific Subcommittee.