Obama announced the United States’ strategic “pivot” to the Asia-Pacific region in January 2012, and a whirlwind of activity there – from Australia to Indonesia to India – marked America’s security diplomacy throughout the year. In Japan, too, worries about Chinese assertiveness have become so powerful that a government that showed considerable hostility to the US-Japan alliance when it came to power three years ago had, by November, begun to trumpet the alliance’s mutual-defense commitments as it confronted China’s claim to the Senkaku (Diaoyu) Islands.