Upon assuming the leadership for the second time in December 2012, Japanese Prime Minister Shinzo Abe called for the formation of a "democratic security diamond [DSD]" to safeguard the maritime commons stretching from the Indian Ocean region to the western Pacific with four of Asia's most prominent maritime democracies -- Australia, India, the United States and Japan -- forming the points of the diamond. The Japanese leader explicitly called on these states to join forces to oppose Chinese "coercion" and to defend peace, stability and freedom of navigation within the diamond. The rehashed quadrilateral concept raises a number of interesting issues relevant to the future security environment of the Indo-Pacific, and for Southeast Asia in par...