This is anything but water under the bridge. After a Hague tribunal ruled that China was impinging on Philippine sovereignty by claiming 90 percent of the South China Sea, Beijing swore to ignore the ruling. They doubled down, declaring they have the right to establish an air defense zone in the territory as well. They took a similar measure in the East China Sea three years ago, inflaming tensions with the U.S. and Japan. But Taiwan, in an unusual move, is taking China’s side, decrying the ruling.