China’s claim it had used “electronic interference” during a confrontation with a Dutch warship in the disputed waters of the South China Sea might signal growing confidence in its capabilities in this area, analysts said. The PLA’s Southern Theatre Command, which oversees the South China Sea, accused the frigate De Ruyter of “illegally entering” waters near the Paracel Islands on Wednesday and repeatedly sending a helicopter into Chinese airspace. Chinese air and naval forces had issued verbal.