The Australian submarine deal is old news at this point. As announced last week, DCNS of France will work with ASC (originally Australian Submarine Corporation) over the next three years to design a new class of submarines to replace the existing six Collins-class boats, built by ASC between 1990 and 2003. The basis of the design will be the nuclear-powered Barracuda-class submarine of the French Marine Nationale. The Australian boats will be diesel-electric, but at 4,000 tons each, they will have enough fuel for an operating range of 12,000 nautical miles—even longer than that of the rather large Collinses. The whole project is expected to consume about A$50 billion in life-cycle costs, and the first boat won’t be ready until 2030, so the program constitutes a serious, long-range commitment. Indeed, in relative terms, it’s such a huge commitment that it makes one wonder what Australians know that the rest of us might not.

Until now, the Royal Australian Navy (RAN) has had a fleet structure akin to that of the (just plain) Royal Navy, at least prior to latter's carrier gap. Broadly speaking, that has meant a fleet with about half as many submarines as surface combatants, and a few small carriers. Specifically, in addition to its six submarines of the Collins class, the RAN is getting three new air-warfare destroyers of the Hobart class, and has eight older anti-submarine frigates of the ANZAC class. The frigates will probably be replaced one-for-one after 2024. A modern and slightly-used transport ship has been acquired a few years ago from the Royal Navy. The fleet also has HMA Ships Canberra and Adelaide, 27,000-ton helicopter carriers with well decks. In addition, I should note that the Royal Australian Air Force will be getting at least 72 F-35A Lightning II fighter jets, and perhaps as many as 100, over the next decade from Lockheed Martin. That’s a meaningful commitment from a country with about 6.8% of the gross domestic product of the United States, and about 7.5% of its population.

Roughly, then, the US is about 14 times larger. And fairly, Australia’s commitment to standing military forces is proportionately smaller. But if the US had a military like that which Australia is building, it’s worth considering how that would be structured. The US Army and Marine Corps would have about 400,000 troops between them, but in a more infantry-centric force, with notably less armor and artillery. Its Air Force and ‘Fleet Air Arm’ would together have 1400 stealthy fighter jets (though no big bombers), 112 patrol planes, and 98 long-range drones. Its Navy would have 14 assault ships, 28 helicopter carriers (though no super-carriers), 154 surface combatants, and 168 submarines.

These numbers, of course, do not make for a clean comparison. There are fixed costs to expanding into further realms of force structure, so countries with smaller budgets naturally maintain less diverse military establishments. There are multiple reasons, for example, that most of the navies which once operated carriers for fixed-wing aircraft no longer do; it’s operationally complex and financially costly. Submarines require serious professionalism, but the tight-knit crews are less complex management problems. All the same, the Australian plan is still a big bet on big submarines. So why such a commitment?

When the dozen-submarines idea was first suggested years ago, I had that question for a few Australian colleagues. But as I have followed the debate on naval power in The Strategist, the Web publication of the Australian Strategic Policy Institute, I have noticed discussions of the serious question of the survivability of any surface ship in high-intensity modern warfare. As Andrew Krepinevich of the Center for Strategic and Budgetary Analysis wrote in a long report last year, the Chinese “precision-strike regime” is potentially very lethal. As Sydney Freedberg of Breaking Defense then termed it, parts of the western Pacific could become a “no-man’s sea”. If that’s so, those long-range submarines might be the only really survivable part of the allied fleet, at least at the beginning of the war. If the brewing disputes with China get nasty, the submarines—including their commandos and cruise missiles—might be one of the few parts of the Australian Defence Force to take the fight forward. And if the Australians have settled on that as military strategy, the rest of us might wonder whether they know something we don’t.

James Hasík is a senior fellow at the Brent Scowcroft Center on International Security, where this first appeared.