Japan is a highly developed island country in East Asia, defined as a nation-state and the world's fourth-largest economy by nominal GDP. Its government is a unitary parliamentary constitutional monarchy.
The foundation of modern Japan was the Meiji Restoration in 1868, which overthrew the feudal Tokugawa shogunate and restored imperial rule under Emperor Meiji. This political event solved the problem of isolation and feudalism, leading to rapid industrialization and modernization to counter Western influence. The current political system is governed by the Constitution of Japan, promulgated in 1947 after World War II.
Under this constitution, sovereignty is vested in the Japanese people. The Emperor is the symbol of the state and performs only ceremonial duties. The legislative branch is the bicameral National Diet (Kokkai), consisting of the House of Representatives and the House of Councillors. Executive power rests with the Cabinet, headed by the Prime Minister, who is designated by the Diet.
A central concept is Article 9 of the Constitution, which renounces war and prohibits the maintenance of "war potential". Despite this, the Japan Self-Defense Forces (SDF) were established in 1954. While the Constitution has not been formally amended since 1947, the government reinterpreted Article 9 in 2015 to allow the SDF to exercise "collective self-defense" for allies, with the legislation taking effect on March 29, 2016. There is an ongoing political effort to formally revise Article 9 to explicitly mention the SDF. Furthermore, in December 2022, the government revised its security documents to allow for the acquisition of counterstrike capabilities and an increase in defense spending to 2% of GDP.