There are few assets on earth as strategically sensitive as the ports flanking the Panama Canal. They sit at the hinge of global trade, where container ships glide between oceans and geopolitics moves just beneath the surface. That is why Panama’s seizure of two major port terminals operated by CK Hutchison, the Hong Kong conglomerate built by Li Ka-shing, deserves more than a passing headline. It is not simply a contractual dispute dressed up as constitutional housekeeping. It is a stress test...