Over the past half century, the United States and its two key allies in Northeast Asia, South Korea and Japan, have established a limited yet effective framework for trilateral defense cooperation. That system has largely remained intact despite a history of bad blood between Seoul and Tokyo, specifically over Japan’s brutal occupation of the Korean Peninsula from 1910 until 1945. But regional observers are now increasingly worried that this edifice is beginning to crumble. The latest sign of trouble was South Korea’s decision last month to scrap a 2016 intelligence-sharing pact with Japan. The General Security of Military Information Agreement, […]