Professor Ratti's research and teaching interests lie in post-World War Two international history, specifically U.S.-European relations, NATO’s evolution and European security and defense policies, and international relations theory. He is particularly interested in the post-Cold War challenges for NATO, Anglo-American relations and Germany in the Cold War and after, and in the broader question of the changing nature of regional and world security.
Professor Ratti's work has appeared in journals such as The Journal of Transatlantic Studies, Diplomacy & Statecraft, The Journal of Slavic Military Studies, The Journal of Middle Eastern Geopolitics, and Mediterranean Politics. His latest volume A Not So “Special Relationship”: The US, the UK, and German Unification explores Anglo-American policy towards Germany during and at the end of the Cold War. He is currently working on a collaborative volume on changing perceptions of security from the Cold War to the return of tension in East-West relations.