Japan is one of the most powerful countries in the world, but has not declared war on another nation since World War II. This is due to its 1947 constitution which contains a "Peace Clause" prohibiting such actions, its security alliance with the United States, international pressure from both regional and global powers, potential economic disruption, and public opinion within Japan being overwhelmingly opposed to war. These factors have all led to Japan's commitment to peace and non-aggression in international relations.