The 1947 constitution and the 1964 Shinkansen: two pillars of postwar Japan

Japan's constitution is the country's highest law. American civilian officials drafted most of it during the post-World War II occupation. Adopted on 3 November 1946, it took effect on 3 May 1947, replacing the 1889 Meiji constitution. The document consists of a preamble and 103 articles across 11 chapters.

The framework rests on popular sovereignty, with the emperor serving as a symbol of the state. It enshrines the renunciation of war, individual rights, and the separation of state and religion. The Meiji constitution had granted the emperor supreme political power. Under the 1946 settlement, his role in the constitutional monarchy is reduced to that of a "symbol of the state and of the unity of the people." He performs purely ceremonial functions, while sovereignty resides with the people. Article 9 renounces Japan's right to wage war and maintain armed forces. Despite this, the country maintains a de facto army in the form of the Self-Defense Forces and hosts a significant United States military presence. Amending the constitution requires a two-thirds vote in both houses of parliament.

MacArthur changes course

Japan surrendered in 1945, and the country came under occupation. General Douglas MacArthur, supreme commander of the Allied forces, instructed Prime Minister Kijūrō Shidehara to draft a new constitution. Shidehara appointed a committee of Japanese scholars for the task. However, in February 1946, MacArthur changed course and presented a draft prepared under his own supervision.

1 October 1964

The Tokaido Shinkansen, the first line in the network, opened shortly before the Tokyo Olympic Games began on 10 October 1964. The 552.6-kilometre route links Tokyo, Yokohama, Nagoya, and Osaka, Japan's four largest cities. The line remains the busiest in the network. In fiscal 2023, it carried 161 million passengers, and more than 6.5 billion since opening.

Before high-speed rail, express trains needed about 6 hours and 40 minutes for the Tokyo-Osaka run. After the Shinkansen opened, the Hikari service, which stops only at selected stations, cut the journey to four hours. The Kodama, stopping at every station, covered the route in five hours. The first Shinkansen trains, the 0 series, ran at speeds of up to 210 kilometres per hour, later raised to 220 kilometres per hour. Construction was financed by a government loan, railway bonds, and a low-interest World Bank loan of 80 million dollars. Initial cost estimates were close to 200 billion yen, but they proved too low. The actual cost came to about 380 billion yen. When the budget gap emerged in 1963, Sogō resigned, taking responsibility for the overrun. In 1962, a rolling stock test site known as the Kamonomiya Model Section opened in Odawara.

Records and reach

The Shinkansen network serves most large cities on Honshu and Kyushu and reaches Hakodate on Hokkaido. An extension to Sapporo is under construction and is due to open towards the end of fiscal 2038. In 2024, the network recorded 385.9 million passenger journeys. The highest speed recorded on the Shinkansen network for conventional rail is 443 kilometres per hour, set by the class 955 (300X) train in 1996. The L0 series maglev reached 603 kilometres per hour in 2015 on the Yamanashi test line, part of the Chūō Shinkansen. Japan is a difficult environment for raising speeds due to frequent earthquakes.