The lead time is too long for submarines if the strategic situation so dire. Unless we get an early delivery announced after the next election to avoid the previous porkbarelling of the Adelaide shipyards. Expanding the RAAF is by far the fastest option inside five years, perhaps ten?
Australia just dumped an Israeli contract on the basis of security concerns and the French submarines had similar emerging concerns. An utter mess and a commercial con job. AUKUS should be the way forward for major equipment procurement.