ASIA- AS 2013 draws to a close, relations between Asia's strongest powers are more difficult, and pose bigger dangers to the rest of Asia, than at any time in the past 40 years. The key question for 2014 is whether, and if so how, those difficulties and dangers can be reduced, or whether they will intensify still further. This may well be the most important issue for the whole region in the year ahead.
Tensions in North-east Asia around the disputed Senkaku/ Diaoyu islands have steadily mounted all year but they took an alarming lurch upwards in the last few weeks. China added a new military edge to its claim over the islands when it declared an air defence identification zone (ADIZ) requiring other powers, including Japan and the United States, to submit to Chinese authority in a large slice of airspace covering much of the East China Sea.
Japan has responded very robustly to China's moves. It has denounced the ADIZ and announced new defence and national security plans that expand Tokyo's military capabilities and seem to presage a drift towards greater nationalism.
The US, meanwhile, has been sending mixed messages. After much tough talk a year or two ago, domestic distractions have raised questions about the durability of President Barack Obama's "rebalancing" to Asia. Strong initial responses to China's ADIZ declaration were followed by softer messages during Vice-President Joe Biden's early December tour of the region.
So it is an explosive mix, with an assertive China, an uncertain US and an anxious Japan. How will it all play out in the coming year? A clearer idea can be obtained by looking more deeply at the perspectives of the three key players.
Let's start in Beijing. For China's leaders, the Senkaku-Diaoyu dispute is not really about these uninhabited islands, or even about the resources that may lie in the waters around them. It would make no sense for Beijing - nor indeed for Tokyo - to risk a military clash with a vital trading partner for such a meagre prize.
Rather, the dispute is really about what kind of relationship they will have in future, as China grows steadily more powerful than Japan, and approaches more closely the power of the US.
China today seeks a bigger leadership role in Asia. It wants to put an end to what it sees as the era of victimhood and grievance that it suffered for over a century, during which Western and Japanese power dominated Asia. It seeks, as President Xi Jinping so often says, to replace this painful era with a "new model" of great power relations.