The United States and Japan have reportedly conducted tabletop exercises assuming the use of U.S. nuclear weapons in response to a crisis in East Asia.
According to a report by Japan's Kyodo News on the 27th, the two countries have discussed scenarios involving the use of U.S. nuclear weapons during emergency situations in East Asia in recent years through their Extended Deterrence Dialogue (EDD).
The two countries reviewed issues related to the use of nuclear weapons, including cooperation based on the situation, public opinion management, and the scope of information sharing, Kyodo News reported, citing sources.
This is the first time it has been disclosed that the two countries have discussed the use of nuclear weapons. Kyodo News assessed, "This signals a strengthening of the U.S. nuclear umbrella amid escalating military activities from China, North Korea, and Russia." It added, "Japan, as the only country to have suffered atomic bombings in war, has advocated for a 'nuclear-free world,' yet it continues to rely on the U.S. nuclear umbrella for its defense."
In December of last year, the U.S. established for the first time guidelines on 'extended deterrence' that involve its nuclear capabilities in Japan's defense and clarified the inter-governmental coordination procedures in the event of nuclear weapon use. While the detailed content of the guidelines has not been made public, it is known to include provisions that allow Japan to convey its opinions regarding the use of U.S. nuclear weapons.
EDD is a working-level consultative body for diplomatic and defense authorities of the United States and Japan. It started in 2010 and is held 1 to 2 times a year. This year, a meeting was held in June in Louisiana.