A former Chinese navy captain was arrested in Taipei harbor on Sunday for illegally entering the area in a speedboat. Authorities in Taiwan believe he may have been part of China’s “grey zone” operations against the island, which involve irregular tactics to evaluate an area without engaging in open combat. The 60-year-old man, surnamed Ruan, is now under investigation and being questioned. His arrest comes amid heightened tensions between China and Taiwan, raising concerns that China may use force to assert its claim on the island.