By Naotaka Fujita
Koichi Arie (58) works at the Ministry of Defense’s National Institute for Defense Studies, which is located in Tokyo’s Ichigaya district. He is a lieutenant colonel and has a Ph.D. in security studies with a specialization in U.S. nuclear strategy. In early July, Arie examined secret documents recently disclosed to the Asahi Shimbun by the Ministry of Foreign Affairs (MOFA). The documents shed light on the Japan-U.S. relationship in the late 1960s.
“The U.S. defense strategy at the time was focused on the concept of response flexibility,” said Arie. “The U.S. aimed to prepare for a wide range of armed conflicts, from guerrilla warfare and conventional battles to nuclear showdowns, by developing sufficient response capability at each level.”
The flexible response strategy was necessary because of the security environment surrounding the U.S. at the time. The USSR had a nuclear arsenal equivalent to that of the U.S. The U.S. was fighting a prolonged war in Vietnam. Moreover, China’s successful nuclear test in 1964 added a new challenge. Arie said that one of the newly disclosed MOFA documents clarified an aspect of the U.S. response to the Chinese nuclear test in context of Taiwan, which was a U.S. diplomatic partner at the time.
The document in question is called the “record of the meeting with U.S. Deputy Assistant Secretary of Defense [Morton] Halperin and State Department Japan Desk Director [Richard] Sneider on Okinawa’s return and other issues.” The meeting took place on Aug. 23, 1967, between senior MOFA officials, including then-North American Bureau chief Fumihiko Togo, and the two American officials who were visiting Japan to attend the Japan-U.S. security sub-committee (SSC) discussions between the two countries’ senior officials.
According to the document, meeting participants discussed their stances on the nuclear arsenal at U.S. bases, which was the focal point in the negotiations on the return of Okinawa. They discussed the flexible response strategy in this context and how to handle tactical nuclear weapons, some of which were in Okinawa and were to be deployed in the event of a contingency in the area.
The document shows that the U.S. considered tactical nuclear weapons to be a valid option for forestalling enemy invasions in localized battles to prevent an all-out nuclear war, even though it cannot be guaranteed that their use would not trigger an all-out nuclear war instead. To this day, the use of tactical nuclear weapons presents a dilemma.
Asked about the U.S. response to China at the meeting, the U.S. side replied that it is worthwhile to have tactical nuclear weapons to serve as a deterrence against a massive ground invasion by Communist China. By saying this, the U.S. underlined the deterrent effect of deploying tactical nuclear weapons, as this would imply that the U.S. would counterattack if China were to invade its neighbor. Sneider also pointed out the need to be prepared to respond with tactical nuclear weapons if China were to advance in the Taiwan Strait. Even through the U.S. could prevent a Chinese invasion in Taiwan with only conventional weapons, “China may misjudge things.” He then cited an incident where the Chinese military advanced to islands in the Taiwan Strait, contrary to U.S. predictions. Sneider was likely referring to a 1958 incident in which the Chinese military fired at Kinmen island, which was effectively under Taiwanese control. The U.S. Navy’s Seventh Fleet was sent to the area in response.
Arie said, “The document gives a glimpse of the U.S.’s flexible response strategy. The nuclear arsenal in Okinawa was regarded as part of its deterrence posture in the event of a contingency in Taiwan.” The meeting participants from both countries were also key negotiators in the Okinawa negotiations.
Okinawa was returned to Japan in 1972 free of the U.S. nuclear arsenal. The joint statement, however, stated that the return would be achieved without undermining the U.S. government’s position, seemingly leaving room for the interpretation that Japan was forbidden to reject a potential U.S. move to bring the nuclear arsenal to the island.
Half a century later, the security environment in East Asia is increasingly strained. China has developed nuclear missiles that can reach not only Japan but also the U.S. China is using this capability to forestall U.S. interference in its policy toward Taiwan. Meanwhile, the U.S. administration under President Donald Trump has withdrawn from the Intermediate-Range Nuclear Forces Treaty with Russia, and is developing more versatile, smaller nuclear weapons.
Arie said: “As long as Japan is under the U.S. nuclear umbrella, the past bilateral negotiations must be accurately understood before launching new discussions on Japan’s defense policy.” (Slightly abridged)