Biden administration scrambles to forestall China’s ambitions in the CaribbeanWASHINGTON—China and Cuba are negotiating to establish a new joint military training facility on the island, sparking alarm in Washington that it could lead to the stationing of Chinese troops and other security and intelligence operations just 100 miles off Florida’s coast, according to current and former U.S. officials. Discussions for the facility on Cuba’s northern coast are at an advanced stage but not concluded, U.S. intelligence reports suggest. The Biden administration has contacted Cuban officials to try to forestall the deal, seeking to tap in to what it thinks might...