The fundamental basis of development is peace and stability. Japan should know because it rose from the ashes of the nuclear attacks of World War II, after previously having conquered much of the Asia-Pacific.
In that gory military contest, Japan sought to expel European colonialists that appeared to be moving closer and closer to Japan after having colonized most of Asia. The post-World War years have largely been peaceful for Japan. Japan grew rapidly, fully utilizing the US military umbrella, while contributing financially to the maintenance of US forces in Japan, mostly on Okinawa—over 50,000 US troops—as well as purchasing advanced weaponry and manufacturing components, through sophisticated electronics and metallurgy.
French President Emmanuel Macron visited Japan last week to stress a “Free and Open Indo-Pacific”. France and Britain, through their colonial naval histories, have sovereignty over islands spread out all over the world and therefore must protect those corresponding 200 nautical miles radius per island Exclusive Economic Zones (EEZ) claimed by them under the United Nations Convention on the Law of the Sea (UNCLOS). In each EEZ, there are seabed mineral and gas deposits yet to be discovered. France has cumulatively the largest EEZ of the world, totalling 11,691,000 square kilometres. India’s EEZ is 2,305,143 sq km, the 18th largest.
The fall of Taiwan would pose existential risks to Japan. The closest Japanese inhabited island to Taiwan, Yonaguni, is only 110 km away. Japan has 6,852 islands within a claimed cumulative EEZ of 4,470,000 sq km. The Japanese Senkaku islands, that PRC disputes the sovereignty over, is another flashpoint. Japan and the US have ironclad collaborations ingrained in multiple security agreements including on nuclear weapons. Yet the Japanese Constitution, written post-War with heavy influence of US authors, is at odds with those security agreements.
Article 9 of the Japanese Constitution reads: “the Japanese people forever renounce war”. Japan and the US signed a defence treaty in 1960. If the US is attacked, it would be interpreted as affecting Japan’s survival, and therefore Japan will constitutionally be able and obligated to use lethal force. The US is committed to Taiwan’s defence, and so is Japan, as it would have to help the US when attacked in Asia.
The US’ Taiwan Relations Act 1979 states “to maintain the capacity of the US to resist any resort to force or other forms of coercion that would jeopardize the security, or the social or economic system, of the people on Taiwan”.