With characteristic precision, Mark Thomson has put his finger on the primary question for Australian defence policy today: not how much should we spend on the ADF, but what do we want it to do? His argument for modest defence spending is properly premised on the view that Australia’s strategic objectives—by which I mean specifically the things we want to be able to achieve with armed force—should be modest. His argument has two elements, one concerning our strategic objectives as an ally of the United States, and the other about our objectives for independent military action. In both cases he argues we can set our strategic objectives pretty low. Is he right?

Let’s start with the alliance side of the story. What do we need to be able to do militarily as an ally of America, given that the huge disparity in power means that we will make no decisive operational difference to any conflict in which we fight at America’s side? There are three ways in which we might weigh this. First there is what one might call a moral imperative to pull our weight rather than free ride, and I must say I share Mark’s sense that free riding is fine as long as you can get away with it. Second there is the question about how low can you go and still ride for free? At what point does our ally stop protecting us because we won’t do our bit? That, of course, depends on why he is protecting us in the first place. On the very credible assumption that he is in the alliance more to serve his interests than ours, the threshold for this is pretty low.

Third, there is the question of whether we are doing enough to influence US policy in ways which are critical to our interest. Here I’m not so sure. We should at least ask ourselves how much we might want to influence US polices in Asia, and how much we’d need to do militarily to have a chance to exercise such influence. I’m torn two ways here. On one hand, Australia’s interests in shaping American policy are clearly very strong. On the other, Britain’s experience in the Middle East over the last few decades, where it has made big contributions and gained very little influence, suggests that the scale of effort needed to have any say in US policy is very great. Further work is needed here before I’d be sure that this is not a good reason to expand our strategic objectives as an ally.

For my money, however, the question of our independent strategic objectives carries more weight. I’m much less sure than Mark is that the United States will stay actively engaged in Asia and continue to play its accustomed role in Australia’s security, especially when we look—as of course we must—three decades ahead. I’m also less sure that even if the United States does stay engaged, its policies will be ones Australia will want to support. So I think it’s very important for Australia to at least consider carefully what we might want to be able to achieve with armed force independently over the next few decades.

The key independent objective worth exploring is whether we want forces to be able to defend the continent independently from a major Asian power. Mark and I would both agree, I’m sure that this depends first, on how serious the risk is that we could face a major power attack alone and second, how much the forces to resist it would cost. Mark seems pretty sure that the risk is so low and the cost is so high that we should forgo this strategic objective. He may well be right, but I’m quite unsure. Partly that’s because I may assess the risk as higher than he does—especially bearing in mind that we might well have a major power right next door by mid-century. But, more importantly, it’s because I think there may be options for Australia to defend itself even from major powers at relatively low cost—by which I mean comparable to the GDP shares we sent in the 1950s and 1960s. If that’s right, then I think adopting that objective and spending that money would be prudent in view of the risks we seem likely to face over coming decades. But it requires an ADF and a defence organisation very different from the ones we have today, and a very different trajectory for defence spending.

Hugh White is professor of strategic studies at ANU and a visiting fellow at the Lowy Institute.