Can one optimal pathway have two lanes? When it comes to AUKUS submarines, apparently yes

“Was the optimal pathway of last week actually not “optimal”? And if so, why was it called the “optimal pathway”?

Was the optimal pathway of last week actually not “optimal”? And if so, why was it called the “optimal pathway”?

By acting defence and national security correspondent Tom Lowrey, ABC News, Wed 3 Jun, 26

For an arm of the government tasked with a fairly straightforward mission — that is, fighting — Defence is famous for wrapping itself in impenetrable language.

Ships and planes are “platforms”, weapons are “capabilities”, soldiers are “personnel” and Australia’s road to running a fleet of nuclear-powered submarines is a “constrained optimal pathway”.

That optimal pathway has come in for plenty of scrutiny in the past few days.

The plan, as of last week, was for Australia to buy two “in-service”, that is, second-hand, submarines in 2032 and 2035, and a third brand-new submarine in 2038.

As of this week the plan is for Australia to buy three used submarines which the government is now arguing has been its preferred option all along.

Defence officials fronting up to estimates hearings this week have been copping questions on the surprise shift.

Was the optimal pathway of last week actually not “optimal”? And if so, why was it called the “optimal pathway”?

“You can absolutely have two constrained optimal pathways,” new Defence Secretary Meghan Quinn told Greens Senator David Shoebridge.

The exchange led Senator Shoebridge to accuse AUKUS of “not only damaging the public purse, but destroying the English language”.

Any economist will tell you constrained optimisation is taught in first year uni. It’s basically finding the best option with the cards you’ve been dealt.

But the exchange highlights the trouble the government is having explaining the changes it’s made and the risk to public confidence in Australia’s biggest ever defence project.

Substituting subs

Back when the “optimal pathway” was first announced in 2023, questions about the complexity of the plans were already being asked……………………….

The new Virginia class submarine would have arrived in 2038, and while details of exactly what it would have looked like aren’t known, it would likely have had some significant differences to its 2020s counterparts.

And the first Australian-made AUKUS submarine would have hit the water in Australia by 2042.

Marles has since argued Australia always held concerns about that plan and our preference from the outset was to acquire three in-service Virginia class subs to try and simplify things……………………..

Defence Industry Minister Pat Conroy addressed the shift on Radio National Breakfast.

“Submarine availability [and] maintenance has improved in the US system, which means that the US Navy feels comfortable releasing a third in-service submarine,” he said.

“That means it’ll be cheaper and simpler for us to run.”

…………………….. For some Australians it might look like the government is arguing a ten-year-old Toyota Corolla (with a responsible owner, of course) is actually a better option than a brand new model straight off the lot.

….It’s getting more real. It’s costing much more money, up to $96 billion between now and 2036, shipyards are being built, and sailors are being trained.

AUKUS is also going to attract much more scrutiny.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, https://www.abc.net.au/news/2026-06-03/two-optimal-pathways-aukus-submarines/106755658