Doubled in size at the very least? Goodness grief Dominic. You'd scare the Kiwis. They'd start to wonder if those "Let's invade New Zealand" ads made for The Gruen Transfer were part of an elaborate maskirovka. I can't even imagine what that would like. Ok, maybe I can try.
But, Army, well, I'd be happy if existing plans were delivered, and even some can be cut back a little. e.g. Land 400 Phase 3. The size and planned structure seems right to me, which means the expenditure is likely about right too.
I could get onboard significant increases in the RAAF and RAN but doubt they would amount to anything quite like doubling. Like, for example, the RAAF could get a fourth F-35 squadron while keeping the Super Hornets, and investing in bringing the Loyal Wingman into service earlier. Plus another Wedgetail or two, a few more MRTTs, and maybe more P-8s. For the RAN, like I said earlier, partly to make the continuous build commitment more realistic, expand the surface fleet to 16-20 warships. And - shock, horror - look at acquiring a light carrier, with F-35Bs and more helicopters.
How do you get to doubling or more though? I am curious.
I am of the view that given a few assumptions (which I think are defensible) if we do not begin with an aim of increasing the air and sea forces of Australia by that sort of margin we will find ourselves
as New Zealand by mid century, that is, strategically impotent on a very essential level. These assumptions are:
1. Meaningfully growing the modern defence force rapidly is probably impossible. The depth of training and expertise required is such that it can only grow slowly, and while capital acquisition can be sped up if need be that is far less efficient than steadily building up over time, and would probably be of inferior quality given our experience with how difficult it is to develop Australia-appropriate capabilities using international suppliers from different contexts. RAN more than the RAAF on this one. If we need a powerful defence force today, we needed to start investing in it at least a decade ago - probably a lot more.
2. Despite their own incompetence, our neighbours are societies on such incredible scales that for us to keep up with the sheer quantity that they will be able to field by mid to late century we need to invest tremendously in our defence force to retain strategic autonomy and significance. It's worth noting that even a country like Thailand will be able to outspend us fairly easily if they approach even half our GDP per capita, and they will during our lifetimes.
3. Beyond just keeping up with our neighbours, we will be living in extremely unstable circumstances. US power has collapsed and we don't know what the floor is, the PRC may or may not meaningfully pursue regional hegemony but they're hardly the only state that could grow to destabilise the region over the next century.
4. We've seen the ADF gutted several times since WW1, and every time it has been due to political incompetence. It is impossible to fully insulate against this, but a larger defence force will be much less vulnerable given that it will represent a much more significant part of the electorate directly and indirectly. I fundamentally distrust every political party in Australia on this matter, including my own, and I'd like to see the ADF less vulnerable to their capricious cuts.
5. Least important but still worth mentioning, I think this would represent sufficient continuous investment and the creation of a sufficiently large skills base to greatly support the industrial and technological capacities of the nation. Not a reason to do it on its own, but a valuable benefit.
I don't have a specific set of capabilities in mind when I say this, nor a number of ships/planes/subs or the like. A doubled RAN/RAAF would be a fundamentally more capable force and could do things the current iterations cannot try to do. I don't think we need a carrier, for example, but that would be within reach with the kind of funding I'm suggesting. I guess the obvious ones would be a lot more subs and a lot more F35s/equivalents, and missiles of various types. I wouldn't stop there of course. Some sort of space capability might become necessary in coming decades, and I rather suspect the nuclear option will be seriously explored if the global order continues to decay.
In terms of Army, IMO the army is strategically irrelevant and therefore mostly a waste of money. I don't say this with the sort of glee you might imagine my fellow inner city lefties would tend to, but I cannot see a situation where Army would actually play a role in defending us other through land-based missiles perhaps. Light infantry and useful in the context of the South Pacific, we should have some at least, but beyond that I don't see the point.
