China has converted scores of obsolete fighter jets into drones and positioned many at forward air bases opposite Taiwan, raising concerns they could be used to help overwhelm the island’s defenses in a conflict. Decades-old Shenyang J-6 aircraft are visible across at least six air bases near the Taiwan Strait —five in Fujian province and one in neighboring Guangdong—according to satellite imagery published by the Washington-based aerospace think tank the Mitchell Institute. China’s investments