The eagle-eyed Greg Sheridan and Sam Roggeveen recently noted that the Australian Prime Minister, Tony Abbot, when announcing a decision to purchase 58 F-35s, hinted that future purchases may be of a different variant to the F-35As Australia has already ordered.

Abbot’s remark implies that Canberra may be considering the possibility of acquiring the F-35B variant (the short takeoff/vertical landing incarnation of the aircraft) suggesting that Australia is pondering the possibility of using at least one of its new LHDs as an aircraft carrier.

While no official announcement has been made to this effect, Abbot’s comment is too intriguing to ignore.  Should Australia acquire an aircraft carrier capability?  If Canberra decides to do so, what would be the strategic implications?

First, the price tag.  Establishing the unit price of the F-35B is a thankless task.  Lockheed Martin, for example, claims that a F-35B (excluding the engine!) will cost around US$104m (approx. AUD$111m) while other estimates suggest the cost may be as high as US$252m (approx. AUD$269m).  Whatever the ultimate cost, these figures serve to emphasise that acquiring an aircraft carrier capability would be extremely expensive.  Given Canberra’s relatively small defence budget, developing this capability would absorb a significant proportion of its finances.

Recently trends also advise caution.  Due to the proliferation of C4ISR capabilities, submarines and anti-ship missiles in Australia’s region, large surface ships have never been easier to locate and attack.  Developing a carrier capability would see Canberra placing a lot of its defence eggs in one slow-moving, highly sinkable basket.

In such an environment, a fleet composed of submarines and smaller, more numerous surface ships seems a better option for the defence of Australia.  Such a fleet would severely complicate any attempt to project force against the continent’s northern approaches.

However, the utility of an aircraft carrier lies less in its ability to defend its homeland than to project force against someone else’s.  By announcing its intention to operate a carrier, Canberra would be sending a strategic message to the region.  Regional states would conclude that Australia envisions the possibility of fighting a high-intensity war in Asia.

China, as highlighted by its response to Canberra’s 2009 Defence White Paper, would likely react badly to such an announcement, further complicating attempts to engage Beijing on issues such as confidence-building and transparency.  Indonesia, Australia’s closest neighbour of consequence, would also be concerned by a capability that would extend Australia’s ability to use strike aircraft over Indonesian territory.  This would further complicate attempts to build a stronger relationship with Jakarta.

Regardless of these arguments against operating an aircraft carrier, an obvious question presents itself: could Australia operate one?  Beyond the technical and logistical difficulties of operating such a vessel, the ship itself must be protected and sustained.  This would require the Navy to devote submarines, destroyers and supply vessels to escorting the carrier.  Given Australia’s limited defence budget, this would risk turning the bulk of the Navy into a carrier escort service, limiting its ability to tackle numerous simultaneous missions.

It’s now useful to consider how and where such a capability would be used.  An aircraft carrier could contribute to humanitarian or evacuation missions in the Asia Pacific region, but acquiring such a capability for these purposes is a disproportionate investment.  An aircraft carrier’s purpose lies in its ability to project, or threaten the use of, force.  It seems likelier that Canberra’s interest in operating a carrier would be prompted by the military options it would endow.

Canberra is already seeking to support the U.S. pivot by hosting marines in Darwin and has a great interest in helping to shape the regional strategic environment in a manner conducive to its interests.  Given that Australia views those interests best served by a strong U.S. presence, I assume that in a conflict Canberra would expect to operate in concert with the U.S. Navy, perhaps even to the extent of embedding its carrier with, say, the U.S. Seventh Fleet.  However, due to the amount of firepower that Washington can bring to bear in Asia, an Australian carrier would make a negligible strategic contribution, though it would be a welcome political fillip.

Should Canberra desire to support Washington in an Asian conflict, operating a diminutive carrier is probably not the most useful contribution it could make.  Far more telling would be a capability to deploy numerous conventional submarines that can haunt littoral waters and ambush enemy shipping or naval forces.  A potent submarine force would be more difficult to detect, harder to sink and would severely complicate enemy deployments by holding large surface vessels at risk.  It would also be welcomed by a U.S. Navy that only operates larger, nuclear-powered submarines which have a limited ability to hug enemy shorelines.

In conclusion, an Australian aircraft carrier would afford decision-makers a wider range of military options.  Indeed, given that developing such a capability would be a long-term project, if, as I have previously mused, the F-35 turns out to be the last manned fighter aircraft Australia operates, the LHD may ultimately prove its worth as a drone-carrier.

However, given the message it would send to the region, the resources required to create and sustain it, the difficulty of protecting it, and the limited strategic contribution it could make in a high-intensity conflict, an aircraft carrier is not the best use of Canberra’s defence dollars.  If Australia wishes to make a strong strategic contribution at sea and support Washington in high-intensity conflicts, it should spend its money on submarines, not slow, vulnerable surface vessels.