Beneath the razzle-dazzle of the long-awaited announcement of the plan for Australian nuclear-powered submarines, the so-called “optimal pathway” illustrates the adage, “Fast, good, cheap: you can only pick two.”

To naval watchers, and perhaps even some doubters, the first two objectives seem plausibly met. The much-feared “capability gap” as the Collins Class nears retirement in the late 2030s will overlap with US and UK submarine deployments to Australia, then with three-five Virginia-class boats purchased from America. This will be followed by the so-called SSN AUKUS class, to be jointly designed and built with the UK, using US technology.