One month ago, the US Commerce Department issued an exceptionally broad set of prohibitions on exports to China of semiconductor chips and other high-tech equipment. The very technical nature of the export controls might obscure just how consequential this new policy could be — perhaps among the most important of this administration. The new rules appear to mark a major shift in the Biden administration’s China strategy, and present a substantial threat to high-tech industries in China, including military technology and artificial intelligence. Washington think tank CSIS called the White House’s new approach to the Chinese tech sector “strangling with...