The China-US relationship began to suffer in early 2018, with tit-for-tat tariffs that would develop into a major trade war. That tension was reflected in bilateral disputes over control of the South China Sea, as well as claims about spying and tech companies. As the year drew to a close, optimism about a trade-war truce reached at the G20 dinner was overshadowed by Canada’s arrest at Washington’s request of an executive from Chinese tech giant Huawei.