[1][2] Stam's research investigates the dynamics of armed conflict both within and between nations, focusing on war outcomes, durations, mediation, and the politics of alliances.
[6] Stam has contributed to projects for the US Department of Defense and the United States Navy's Joint Warfare Analysis Center and conducted surveys in Russia, Rwanda, India, and the U.S. His research on the Rwandan genocide, featured in a BBC documentary, and his work in Gujarat, India, where he assisted in surveying 120,000 households across 1,800 villages to track discrimination and violence against sub-caste populations, provide insights into Indian Caste discrimination.
[3] Building on his research interests, Stam studied why democracies win wars–focused on military effectiveness, and concluded that superior logistics, initiative, and leadership led to stronger battlefield performance.
[15] However, he highlighted that these advantages diminished in prolonged conflicts, and after 18 months of war, autocracies persisted and ultimately gained the upper hand through their military-industrial capacity and strategy.
[17] Subsequently, in 2002, he co-wrote a book titled Democracies at War, which Brandon Valeriano described as "an important empirical contribution to the fields of political science and military strategy.
"[22] In 2004, he co-authored The Behavioral Origins of War, which Philip A. Schrodt praised as "potentially the last important one,"[23] and Lawrence D. Freedman noted that the authors "offer an ever more refined analysis.
In addition, he collaborated with both the prosecution and defense at the International Criminal Tribunal for Rwanda and uncovered data from NGOs documenting the 100 days of violence.