Fresh from consolidating power with a third term at home, Xi Jinping struck a largely cordial tone at the G20 summit in Indonesia, but don’t expect a change in China’s often aggressive “wolf-warrior” diplomacy. While laying down a hard line on Taiwan, the Chinese president’s three-hour meeting with Joe Biden was described by the US president as “candid and clear” on subjects ranging from Taiwan to trade. After China accused the US of breaching the “One China” policy in its pledge to protect Taiwan, Biden reassured Xi that the US remained committed to the policy and “a new cold war”...