His research focuses on several areas, including political ethics, ideology, and just war theory. Campbell has presented several papers to the International Studies Association, including “Constructing the Probability of Success: History, Just War, and 'Winning' the War on Terror,” and has been published in Political Science Quarterly. He received his B.A. from William Jewell College before receiving his M.A. from the University of Missouri at Kansas City. In 2015, Campbell received his Ph.D. from the University of Kansas.