The nuclear option

Australia's fast track to acquiring nuclear-powered submarines from the United States and Britain puts a gulf between it and its close security ally, New Zealand.

- BERNARD LAGAN

It's not just because of the cost of the vessels - up to A$368 billion ($395 billion) over the next 30 years - but also because Australia is shifting its decades-long focus on the defence of the mainland to one of projecting lethal force into far-distant waters, the realm of China.

All this is occuring with the barest of public debate and a lean case put forward by the Albanese Labor government.

The move will further embed Australia with the US military and, by implication, draw it deeper into the US foreign policy web - especially as it relates to the US defence of Taiwan, should Beijing attempt to occupy the territory.

The nuclear submarines will come first from the US, which will supply up to five secondhand 115m, 135-crew Virginia-class boats. Later, eight vessels of a new hybrid British design, equipped with a US combat system, will be built in Adelaide.

They are being supplied under the new Aukus defence pact between Australia, Britain and the US - but not New Zealand.