Dianne Pfundstein Chamberlain, PhD, is an associate research fellow with the Saltzman Institute of War and Peace Studies at Columbia University. She was formerly an Assistant Professor in the Department of Political Science at the University of Massachusetts, Amherst, and a Postdoctoral Research Fellow in the International Security Program at the Belfer Center for International Affairs, Harvard Kennedy School. She is the author of Cheap Threats: Why the United States Struggles to Coerce Weak States (Georgetown University Press, 2016).

Image: U.S. Army Soldiers, assigned to 101st Combat Aviation Brigade, 101st Airborne Division, hover over a landing zone in UH-60 Black Hawk helicopters during air assault training at Jalalabad Airfield in eastern Afghanistan, Sept. 16, 2015. U.S. Army photo by Capt. Charles Emmons.