The rule of law has been Japan's trump card in its ongoing rhubarb with China over competing territorial claims in the East China Sea.

In the war of words with Beijing, Tokyo has gained moral authority by criticizing its rival for not abiding by the rule of law and trying to change the status quo through unilateral actions and military coercion. Early last year Keiichi Hayashi, Japan's ambassador to the United Kingdom, responded to his Chinese counterpart's assertion that Japan was acting like "Harry Potter" nemesis Voldemort with a similar dig of his own.

"There are two paths open to China," Hayashi wrote in a Telegraph op-ed. "One is to seek dialogue and abide by the rule of law. The other is to play the role of Voldemort in the region by letting loose the evil of an arms race and escalation of tensions."