The free-trade zone that China, Japan and South Korea agree is vital to economic growth is being threatened by one of its proponents, Japanese Prime Minister Shinzo Abe. Just days after he agreed with President Xi Jinping to push forward negotiations and corralled the Group of 20 leaders at their summit in Osaka to “strive for a free, fair, non-discriminatory” environment for global trade and investment, his administration imposed restrictions on South Korean technology exports . Animosity is rife between the neighbours over issues languishing since the Japanese occupation of the Korean peninsula, but Tokyo claims national security has prompted its action. With Seoul warning of retaliation including product boycotts, a diplomatic resolution is urgently needed to head off the risk of another trade war. There are shades of US actions against the Chinese technology giant Huawei in Japan’s moves. Tech firm Samsung is among South Korean companies hit by last week’s tightening of controls on chemicals needed to produce chips and displays for smartphones and televisions. South Korea seeks US intervention to heal deepening rift with Japan A longer processing period for exports has been imposed and, while not a ban, over time it could lead to a curbing or even shutting down of semiconductor production. Following the lead of Huawei by seeking self-sufficiency would seem to make sense, but the interconnectedness of global supply chains makes that difficult and it would be better for the region’s tech powerhouses, China, Japan and South Korea, to work together. United States President Donald Trump’s protectionism has brought economic uncertainty to northeast Asia. Xi and Abe were spurred to meet ahead of the G20 and promised closer relations. Why Japan-South Korea ‘trade war’ is good news for China But there were no such talks between the Japanese leader and South Korean President Moon Jae-in, with disputes involving forced labour and the sex slavery of hundreds of thousands of Koreans during World War II hampering ties. A South Korean supreme court ruling last October heightened tensions; it ordered two Japanese companies to pay compensation to four South Koreans, prompting Tokyo to protest that all claims were settled by a bilateral treaty restoring diplomatic relations in 1965. Trump’s trade war is being driven by a re-election bid and with the upper house of Japan’s parliament holding elections on July 21, Abe’s sights are also set on political gain through wooing conservative voters. But he does not seem to care that companies and consumers may suffer through lost business and higher prices. His concern should be fighting trade wars as he promised at the G20 , not joining them. As he is doing with Xi, he should be mending ties and working with Moon so that all three nations can use their strengths for joint benefit.