Way to be passive aggressive. China has demarcated an “air-defence identification zone” over an area of the East China Sea that includes islands also claimed by Japan. The Senkaku islands (or Diaoyu, as they’re known in China) are an escalating source of tension between the two countries. "Setting up such airspace unilaterally escalates the situations surrounding Senkaku islands and has danger of leading to an unexpected situation," Japan's foreign ministry said in a statement. Taiwan, not one to get left out, also lays claim to the islands and said that its military would take measures to protect national security.