Kevin Weng's research covers the linkage between state-building and battlefield performance, with a specialized focus on Chinese politics. His dissertation traces the process through which different methods of taxation led to logistical constraints on the military strategies of the Chinese Communists and Nationalists during the Sino-Japanese War and the Chinese Civil War.

Other research interests include the use of contradictory diplomatic signaling in crisis bargaining, civil-military relations, and state-militia relations.