The four excellent responses to my post on China-Japan relations all present important points about Japan's situation and its options in the face of China's growing power. Just to recap, my piece questioned whether Chinese political and military pressure on Japan in the East China Sea is as counter-productive for China's strategic objectives as many people believe.

That depends of course how Japan and the US react to it. I suggested that it would serve China's aim of weakening US leadership in Asia if it undermined Japan's confidence in the US alliance by exposing America's reluctance to support Japan militarily against China. This would be seen as a win in Beijing even if Tokyo responded by building up its own defences, because China would rather face Japan than America as a strategic competitor in Asia.

My old colleague and valued sparring partner Malcolm Cook argues that if Beijing's leaders thinks this way, they are wrong. He says China's pressure on Japan has strengthened the US-Japan alliance, and cites Abe's measures to 'normalise' Japan's military role as evidence.

This is a key issue: if Malcolm is right than the Chinese really are making a big mistake in the East China Sea. That is why it is so important to test our judgments on it quite carefully. I'd offer Malcolm two sets of thoughts about it.

First, how confident is Tokyo that America really would be willing to go to war with China over the Senkakus? This is not at all a hypothetical issue for Japan. Malcolm seems to think Tokyo has complete faith in US military support. I am much less sure. That's partly because of what people in Tokyo say to me. It's partly because of what Americans say, and don't say. The polite word for America's signals over the Senkakus is 'mixed', and they remain so even after Obama's Tokyo statement earlier this year. Above all, it's because of the military realities. When we look at what would happen if the US actually did fight China over the Senkakus, we can see why Japan would be wise to doubt US support. 

Second, what is Abe's motive in strengthening Japan's military posture? Malcolm is sure that it is to reinforce the US-Japan alliance, not to replace it. I think it is aiming to do both. Prime Minister Abe no doubt hopes that by doing more to support America in Asia it will strengthen US capacity and resolve to preserve the status quo. But I have argued before that this won't work, and it seems that Abe sees that as a real risk. So his new policies are also intended to lay the foundation for Japan to look after itself if US support should fail.  

If these thoughts are right, China would be right to think that its assertiveness will weaken the US-Japan alliance, and leave Japan with only the two choices I mentioned.

However Dhruva Jaishankar's elegant post raises a different possibility.

He suggests that even if Beijing is right to expect a weakening US-Japan alliance, it might be overlooking a third Japanese option. Rather than meekly submitting to Chinese primacy or reconstituting itself as an independent great power confronting China, Japan could join and perhaps lead a coalition of regional powers along the lines recently suggested by Rory Medcalf and C Raja Mohan. This is what Abe himself may well have in mind. 

Rory's and Raja's fine paper deserves a post to itself, but let me just say here that I think the possibility that they and Dhruva raise is less threatening to China's ambitions than one might suppose. That is because, whatever might be its diplomatic attractions, the strategic potential of such a grouping against China is very limited. Ultimately, it depends on how willing its members are to go to war on one another's behalf. In Japan's position, of example, the value of a regional coalition would depend on whether India, Australia, Vietnam and others would be willing to go to war with China to support Japan over the Senkakus. I bet they wouldn't, and I think China would bet that way too. So without America, Japan is on its own.

Of course China is keen to make sure it stays that way. That is why, as Christopher Pokarier quite rightly says, China is going out of its way to stigmatise Japan's defence policy changes as 're-militarisation'. Like him I think this is quite unjustified. Japan has a perfect right to defend itself just as any other country does. It has almost 70 years of good international citizenship behind it, from which the historical revisionism of Prime Minister Abe and his circle does not materially detract. And, above all, Japan today lacks the strategic weight to threaten China or any country that Beijing chooses to support. This is why I don't think we should be too worried about Japan reconstituting itself as an independent strategic power in the new order that is emerging in Asia as the old one passes away.

Which brings me finally to Brad Glosserman's piece. Brad is another favourite sparring partner. As always, he goes straight to the core questions. I absolutely agree with him (and with Malcolm) that the best thing for Japan would be to continue to depend on America. But I do not believe that is possible, because the old regional order in which that posture worked so well for Japan has been overturned by China's new power and ambitions.

The impact on Japan's situation is a simple matter of what we might call Newtonian strategy. As China's wealth and power grows, the costs to the US of conflict with China grow, and the threshold for US support to Japan against China goes up accordingly. It has now gone up far enough that America may no longer be willing to support Japan militarily over issues like the Senkakus which Japan rightly regards as vital. I think perhaps many Americans are in denial about this. I don't think many Japanese are. The Chinese understand it very clearly, and that is the message their actions over the Senkakus are trying to convey.

So what can Japan do? I think it faces a binary choice: accept Chinese primacy or try to preserve its full political and strategic independence. Which path Japan takes will depend, inter alia, on what kind of regional hegemon China might become. If it turned out to be as benign as the US has been in the Western Hemisphere, then a future for Japan as Asia's Canada might not be so bad. But how trusting are the Japanese willing to be? And what have the Chinese done to earn Japan's trust? 

And the alternative? I may have misled Brad by describing Japan's other option as a return to 'great power' status. I do not mean that Japan would need to compete with China for hegemony in Asia, or assert a sphere of influence of its own to match and balance China's. In the right regional setting Japan could establish itself as a great power on equal terms with China, without seeking hegemony or a sphere of influence. For reasons I set out in The China Choice, that regional setting would need to resemble the nineteenth-century European Concert of Powers: a Concert of Asia. Only as an independent great power in that kind of setting can Japan be secure over coming decades, unless it is willing to accept subordination to China.

Image courtesy of the White House.