The defence case for a bigger Australia

When the Second World War ended, Australia decided it needed more people. Lots more.

Why? It was in large part a facet of defence policy: governments of the time felt that Australia had to get bigger in order to protect the massive continent that had so recently come under threat from imperial Japan. “Populate or perish”, went the slogan.

Australia has had a strange journey since then. While its population has risen from approximately 7.5 million in 1945 to 28 million today, the defence motivation that triggered this rise is now almost entirely absent. The objectives listed on page 37 of Australia’s 2023 Migration Strategy don’t mention defence. The document acknowledges that migration “contributes to Australia’s security” but mostly consigns that motivation to the past.

The reluctance to discuss the links between population and security might be motivated by justified embarrassment about Australia’s past, as the “populate or perish” mantra carries associations with racialised panics about Australia being over-run by Asians (“the yellow peril”).

Or maybe it’s because the nature of warfare has changed. In 1945, war was highly labour-intensive, but capital is now the overriding consideration – wealth matters more than population, especially for an island nation that doesn’t need a large standing army.

Labor MP Andrew Leigh gave a speech on population policy to the Lowy Institute in 2014 in which he made another argument, that population doesn’t offer much protection anyway: “In national defence, population size matters less than you might think,” Leigh said. He quoted an analysis of 44 conflicts from the 20th century that found the country with the smaller population won about half the time.

Of course, this argument sets aside those wars that were never fought in the first place. We can assume that one reason El Salvador has never invaded the United States is that San Salvador’s army is so small. Or, to bring the point closer to home: if you believe that population size has little bearing on the effectiveness of national defences, you would presumably argue that Australia would be equally secure from foreign military threats with a population of, say, 16 million people rather than 28 million.

That’s not an unreasonable view, because a number of variables are at play. Scale matters but much also depends on how devoted the nation’s citizens are to national defence (for example, Finland, Israel and Switzerland are known for their strong societal commitment to universal conscription). Then there’s the question of how much governments are prepared to spend. A bigger population typically means a larger tax base from which to draw a defence budget, but a nation could also choose to keep its population stable while devoting a larger proportion of its tax income to defence.

Nevertheless, even with these variables in mind, there are some hard limits to what can be squeezed from a given population. Australia could adopt a more martial culture like that of Finland, Israel and Switzerland, but we wouldn’t want to go as far as North Korea. And Australia could spend a greater proportion of GDP on defence, but that has costs for other government services and the economy as a whole. At a certain point, the only solution is to grow out of the problem.

Finally, there is the question of what you want your military force to be capable of doing. In a recent podcast interview, former head of Australia’s Home Affairs Department, Mike Pezzullo, who had earlier served as a senior strategist in the Defence Department, said he would like to see Australia’s population rise to 40 million by the middle of the century so that it can support a defence force of around 100,000, surging to 200,000 in an emergency.

For Pezzullo, this is the kind of defence force Australia would need:

“…for the most credible contingency that we would face, which is basically a theatre-wide war where Australia’s not been attacked directly … but we’re part of a theatre war which extends from the middle of the Indian Ocean probably right up to Alaska. And it’s a bit more like the conflict that we faced in 1942.”

This is a brief exchange from a much longer interview, and there’s not much additional context offered to understand Pezzullo’s “credible contingency”. But he appears to be saying that Australia would and should participate in what he calls a “theatre” war (presumably alongside the United States, and presumably against China) even if there is no direct territorial threat to Australia.

This opens up a much broader debate about the purpose of Australian defence policy. Should it be focused on operating alongside the United States to preserve a favourable balance of power in Australia’s region? Or is the US unlikely to be reliable enough to support such a stance, forcing Australia to adopt a narrower continental defence strategy, unaided by our ally? And if the latter, might Australia need an even bigger population than Pezzullo contemplates?

At the very least, we can say that the link between immigration and national security is inescapable, no matter how uncomfortable it is to discuss.