Thus, it was startling and refreshing to hear Hudson Institute's Senior Fellow Jun Isomura give that rare answer. He brushed off cooperation with the Koreans because they are just too emotionally unstable.
He spoke at a September 21, 2018 program introducing Hudson's report U.S.-Japan Strategic and Operational Cooperation on Remote Island Defense, that gave lay recommendations for how the United States and Japan can strengthen their operational and strategic cooperation in defense of the Ryukyus. The writers believed that the U.S. would more likely come to the defense of the Ryukyus (Okinawa Prefecture, Pop 1.5 million), sparsely populated islets in the East China Sea, than of Taiwan, which is at the end of this island chain.
Below is the clip of Mr. Isomura explaining why Japanese leaders avoid including their Korean counterparts in regional plans.