Jailed Hong Kong opposition activist Joshua Wong Chi-fung has admitted instigating international sanctions against central and local authorities six years ago, such as urging foreign businesses to avoid investment in mainland China and petitioning an Israeli forensic tech firm to terminate its services for the city’s police force. The High Court heard on Wednesday that Wong, 29, had conspired with fugitive ex-lawmaker Nathan Law Kwun-chung, 33, and others to garner international support for...