The book explores the evolution of the debate on the scope and meaning of the constitutional “pacifist principles” (or “pacifist clauses”) in Italy (article 11 of the Italian Constitution) and Japan (article 9 of the Japanese Constitution) generated by the war in Ukraine. The “pacifist principle” is a fundamental principle of both the Italian and Japanese Constitutions. Article 11 of the Constitution of Italy provides that “Italy rejects war as an instrument of aggression against the freedom of other peoples and as a means for the settlement of international disputes”. Article 9 of the Constitution of Japan provides that “Aspiring sincerely to an international peace based on justice and order, the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as means of settling international disputes”. The actual scope of these provisions has historically been the object of a heated legal and political debate in the Italian and Japanese societies alike. It is not controversial that the “pacifist clauses” allow (and even oblige) Italy and Japan to recourse to “war” as a means of self-defence of last resort, to ensure the survival of the democratic constitutional system when faced with an existential threat (a “war” of invasion/annexation). Scholars, however, disagree on whether (and to what extent) these provisions allow Italy and Japan to provide aid to a third Country engaged in a war of their own. The book explores this dilemma from an interdisciplinary perspective, drawing on legal, historical, philosophical, and comparative approaches.

Giovanni Cavaggion is Associate Professor of Constitutional and Public Law at the University of Milan, where he teaches Constitutional Law, Public Law and European Values and Cultural Rights. He authored the books Diritti culturali e modello costituzionale di integrazione(Turin, 2018), La formazione del Governo. Aspetti e problemi tra quadro costituzionale e nuove prassi (Turin, 2020), and I diritti della maggioranza nel costituzionalismo contemporaneo. Possibili derive illiberali della difesa dell'identità nazionale(Turin, 2025), as well as over 50 other articles and book chapters with national and international publishers. He is the coordinator of the Jean Monnet project “European Values and Cultural Identities: Constitutional Challenges of the Promotion of the ‘European Way of Life’” (EU-VALUE) and the principal investigator of the SEED project “The ‘pacifist principle’ in the Italian and Japanese Constitutions in the wake of the war in Ukraine” (PEACE-ITA-JPN). His research interests include, among other things, the multicultural society, the protection of fundamental rights, multilevel constitutionalism, the European integration process, the fundamental values and principles of the European constitutional tradition.