Many people believe that Australia would never need to defend itself unaided. Even if US support cannot be taken for granted ^[1] in the future, they think that we needn’t ever stand alone, because we have many potential allies among our neighbours. These optimists expect that countries like Japan, India and Indonesia, to name just a few, are natural strategic partners because they share our concerns about China.

I’m more pessimistic. That’s not because I’m against alliances. On the contrary, as I argue in How to defend Australia ^[2], we should actively seek regional allies. Only by working with them can we hope to protect our wider strategic interests and thereby limit the risk of a direct military threat against us. Moreover, we should structure our forces in some specific ways to allow us to do so effectively.

But we cannot use such allies as a basis for our strategic posture and force planning. That is why I argue that we should plan to defend Australia alone. This might come as a surprise in view of the much-hyped network of defence partnerships we have built up over the past few decades. Don’t all these partners count as allies?

Well, yes, if we mean that we might cooperate diplomatically to try to resist China’s influence. But that kind of thing doesn’t count when we’re talking about military strategy and force structure. What matters then is whether we can rely on others to fight to help us defend our territory or vital interests.

The only kind of alliance that counts for defence policy is one expressing clear undertakings to fight under certain circumstances. Strictly speaking, we have only two military alliances with neighbours. One is with New Zealand under ANZUS, and the other is with Papua New Guinea under the 1987 joint declaration of principles. The Five Power Defence Arrangements pact doesn’t count because it commits us to help defend Malaysia and Singapore but doesn’t commit them to help us.

The optimists say this is changing. They point to the Quad as evidence that countries throughout Asia are becoming more willing to cooperate strategically to counter China’s growing power and reach. But the busy make-work of defence diplomacy—content-light meetings, scripted exercises, carefully worded joint statements and low-level logistics agreements—all fall a long way short of the kind of serious strategic undertakings that we could plan our defences around.

Nonetheless, many people are confident that true alliances will emerge as and when the need becomes clear. They take it for granted that fellow democracies like India, Indonesia and Japan will be willing to make big sacrifices to help us resist Chinese pressure or threats. And they presumably also take it for granted that we will be willing to make big sacrifices to support them.

This is just wishful thinking, unless we have solid reasons to think that these countries will identify their most vital strategic interests with ours. The common assertion that they will because we all profess democratic values does not suffice. Even if our political values were much more closely aligned than in fact they are, they would not forge effective alliances. History—the only guide we have—suggests that shared values count for little in decisions for war. Shared fears of a common enemy are what count. Military alliances work and endure only when the parties are convinced that their own security depends directly on the security of an ally, and the more direct the dependence, the stronger the alliance will be.

The question, then, is whether shared anxiety about China ensures a sufficient alignment of objectives between us and our Asian neighbours to sustain effective regional alliances. Does India’s or Japan’s security from China depend on ours, and vice versa?

I think the answer is no, for reasons that are rooted deep in Asia’s strategic geography. To see why, it helps to compare Asia with Europe.

Not surprisingly, much of our thinking about potential alliances in Asia draws—explicitly or implicitly—on European models, especially NATO. But Europe’s strategic geography is very different from Asia’s. In Europe a large number of potent strategic actors are jammed together in a tight space. Any major shift in the distribution of power has immediate implications for all of them.

A glance at the map makes it clear that Russia can attack Germany much more easily if it controls Poland and can attack France much more easily if it controls Germany. That means France’s and Germany’s security from Russia depends on defending Poland. That makes for a powerful convergence of strategic objectives between all three countries in the face of a Russian threat.

East Asia is different, in two related ways. Its key strategic powers are much further apart, and they are mostly connected by sea rather than by land. That is even true of India and China, because their long border is so mountainous as to be impervious to large-scale land forces.

That makes it far less clear that Japan’s or India’s vulnerability to Chinese attack depends on Australia’s security, or vice versa. China can quite easily threaten one of them without threatening any of the others. It doesn’t need to go through Japan to attack Australia.

Strategic geography is one of the reasons why there is no Asian NATO, and why the attempt to establish one—SEATO—failed so dismally.

This line of argument does not, of course, apply with the same force to Indonesia. Its position makes its security critical to ours, which makes it highly credible that we would fight in its defence—just as Britain has at times fought to defend France—and (perhaps a little less likely) that it would fight to defend us. Indonesia also has the potential to become a major power and thus a very valuable ally. That is why, as I’ve argued elsewhere, Indonesia may well be our most important strategic partner in the decades ahead. But as the example of Britain and France attests, close neighbours make awkward allies. We can never take Indonesia for granted.

And that means that we cannot count on Japan’s or India’s or Indonesia’s or anyone else’s help if we are threatened, just as they cannot count on ours if they are. A big factor here is that, for all of us, China is a valued partner as well as a scary neighbour. It would have to become a lot less valued, or a lot more scary, before Asian powers overcame the centrifugal effect of geographical dispersion and coalesced against it. And Beijing may well be smart enough to stop that happening: divide et impera no doubt translates well into Mandarin.

None of this means we have no chance of building alliances with countries in our region. Nor does it mean that we shouldn’t build a defence force that would allow us to fight alongside them if we can. But it does mean we shouldn’t base our strategic posture on the optimistic assumption that we will always find a powerful friend when we need one. We can count on New Zealand, but other than that, we need to plan to fight alone.