From one perspective, China's declaration of a new Air Defense Identification Zone (ADIZ) over the East China Sea is a perfectly natural step. Such zones have been widely accepted under international law and practice for decades, and they have been established by many countries.
But the circumstances in which a step like this is taken can make a big difference to its consequences and implications. In this case, the circumstances in which China's new ADIZ has been declared are very significant indeed. It could well shape the whole strategic future of Asia.
That is because the ADIZ covers the Diaoyu Islands (known as Senkaku Islands in Japan) claimed by both China and Japan. The dispute over the islands has escalated over the past year as both sides have shown that they are willing to defend their competing claims with armed force.
This alone gives Beijing's decision to declare the ADIZ added significance, because it has inevitably been seen as a further step in this escalating dispute. But that is only the start, because the Diaoyu dispute itself must be seen in a wider context.
The issue is not really about possession of a handful of uninhabited rocks. Even the resources that might lie in the waters around them would not be worth the risks to either side of a clash with the other. But control of the islands has become a symbol of a much bigger issue - the question of who leads Asia.
It might seem puzzling that such a big question should depend on such intrinsically insignificant territories, but the explanation is quite simple. As China's power grows, Japan worries that it will find itself subordinate to China's regional leadership, which would harm Japan's prospects. It fears that minor concessions to Beijing over the disputed islands would imply that it acknowledges China's regional primacy and accepts its own subordination. Tokyo is determined not to do that.
On the other hand, Japan's leaders know that China is vitally important to their country, and they dread an armed clash. They look to the US to shield them from this risk and from the pressure they feel from China.
The US-Japan alliance therefore draws Washington directly into the rising tensions between China and Japan in the East China Sea. That has huge implications for Washington's own position in Asia.
If Japan loses confidence in the US, it will abandon the alliance and look to its own defense. Japan remains a rich and powerful country easily able to defend itself if it chooses, and there are already signs that it is moving this way.
If that trend continues, the US will lose Japan as an ally, which would gravely weaken its place as the leading power in Asia. And that would clearly enhance China's own leadership position.
Actions like Beijing's declaration of the ADIZ therefore confront Washington with a very uncomfortable choice. It must either support Japan by opposing China, which risks escalating rivalry with China at huge potential cost and risk. Or it must step back from supporting Japan, which risks undermining its leading position in Asia.
China's leaders are sophisticated strategists, and they no doubt understand all this very clearly. That suggests they deliberately intend to confront Washington with this uncomfortable choice.
Moreover, they presumably expect that faced with this choice, Washington will decide to step back from supporting Japan rather than risk escalating confrontation with China.
If so, they have been proved right so far. After strong initial objections to Beijing's ADIZ announcement, Washington seems to have scaled back its reaction and downplayed its commitments to support Japan militarily in the event of a clash with China.
Specific reference to these commitments was notably absent from Vice President Joe Biden's remarks when he visited Japan and China recently.
All sides need to recognize the need to compromise if conflict is to be avoided. That applies to not just the immediate disputes in the East China Sea, but the much wider questions about the leadership of Asia.
In the future, a peaceful order for Asia will need to accord China a substantially greater leadership role than it has had in recent decades.
But it will also have to accord a significant role for the US, and satisfy Japan's need for security and independence.
Leaders in all three countries will need to work hard if they are to create this kind of new order while avoiding the very real risk of escalating rivalry and conflict.
The author is professor of strategic studies at the Australian National University in Canberra. firstname.lastname@example.org