The noise will be all about the submarines; but that’s not where the punch will land. It’s designed, instead, to demonstrate there’s been a decisive shift of power. You can throw both Rudd’s 2009 white paper and Gillard’s paper last year into the bin. His message is that there’s a new government in town and it won’t be bound by its predecessor’s ambitious plans that can’t be funded. The direction of defence may have wobbled a bit since the election, but Johnston is determined to seize the steering-wheel and demonstrate he’s in the driving seat.

The government believes there’s an urgent need for this message, The dries in cabinet are increasingly angry about what they perceive as a wasteful and incompetent defence industry that assumed the incoming government would simply open its wallet and say, “help yourself”. That’s not the case. There’s a significant faction that can’t see the point in paying a huge premium simply to get something Australian made. Particularly when – as with the air warfare destroyers – there are massive problems putting the equipment together because the parts don’t match. That’s part of the reason why the forces are lucky they’ve got Johnston. He’s as close to a big-spending, build-it-here type of minister as this government’s likely to get. And this is why his warningshould sound an alarm.

The key point Johnston will make is that there’s nothing sacred about the idea of 12 subs that was suddenly nominated in the 2009 white paper. The scuttlebutt has it that the number was simply plucked out of Rudd’s head: there was no concrete military analysis insisting on the need for so many boats. Far more importantly, however, the requirements for the capability were never detailed and nor was the concept funded. Johnston’s aim is to match the ambitions outlined in the paper to the funding and strategic direction of defence. This speech fires a shot across the bows of those who believe nothing has changed since the election.

It was only a matter of time before the submarine project came unstuck. Building these vessels is the equivalent of designing a spaceship. This doesn’t mean we can’t do it – it just means that doing so consumes an enormous amount of resources, and these can’t be used elsewhere. Andrew Davies of the Australian Strategic Policy Institute estimates the cost of simply building a dozen submarines would, by now, have climbed to $40 billion. Investing in such a large fleet would completely unbalance the navy. Nothing would be left over for the surface vessels. And although a report from British engineering specialist John Coles released on Tuesday indicates there’s been a “remarkable” turn-around in meeting performance benchmarks, it seems fair to assume that this government is determined not to be held over a barrel by anyone.

This is where the Japanese come in. Although the Collins class submarine is currently performing well (with three of the six boats ready for sea), the latest Japanese design has a crucial advantage. The Soryu design (the name means dragon and was the name of an aircraft-carrier sunk by US aircraft at Midway in 1942) has “air-independent propulsion”, meaning it doesn’t need to surface like the Collins’. This is such a critical breakthrough that Japan has indicated it’s not willing to share the technology – although it might be persuaded to sell the engine. And that’s what the navy’s been concentrating on since 2012.

Contacts were intermittent until Rear Admiral Rowan Moffitt, the head of the program to replace the Collins, visited Japan in July that year. He was very impressed by the Kawasaki engines, as were defence scientists who examined them – but the sticking point always was Japan’s willingness to transfer the technology.

Johnston’s speech will, essentially, throw everything up in the air. He’s demonstrating that it is the Coalition that will now decide which elements of the force structure it will catch, and what it will discard. Nothing is decided –that will wait for the white paper – but the government is showing that it will be deciding the future shape of defence and the Rudd years are over. Equipping the forces will require the balancing of capability requirements with fiscal ones. The submarine is simply the first step.

Nicholas Stuart is a Canberrra writer.