By Mark Kenny

A version of this article was originally published by The Canberra Times.

JUST a few short years ago, it was said in the halls of power that Australia did not have to choose between its security and its prosperity - between its enduring strategic guarantor, and its economic meal ticket.

But that comforting bromide lasted only as long as Beijing played along, and in the past five years it pointedly stopped doing so. This is the critical insight of the new AUKUS pact and of Australia's momentous admission into the nuclear-powered submarine club - only the seventh nation globally to join up.

Australia's new posture should not be a surprise anywhere around the Pacific Rim. Indeed, Beijing itself wanted the world to know that the China of the 2020s is not the benign giant it was coming into this century. Its aggressive wolf-warrior diplomacy is aimed precisely at communicating this intimidating new presence. Likewise its willingness to expel or jail foreign citizens, and use trade as an instrument of foreign policy.

The colossal growth of its weaponry, its militarisation of the South and East China Seas, and its direct sabre-rattling over Taiwan, signal a dangerous new game.

The currency of this new game is force - both real and perceived. President Xi promises re-unification of greater China and in the last 24 hours called for a "great wall of steel" to protect China's interests. China's economy rivals America's and its navy - not so long ago dismissed as small compared to the US - is now larger, if not yet as capable.

Harsh rhetoric backed by actual capacity must be taken seriously and that is what the AUKUS alliance countries have done. Whether this makes confrontation less likely in the short term is debatable.

The Albanese government has concluded that the greatest peacetime military build-up since the Second World War requires a response. It has made its choice, but it still hopes to repair Sino-Australian relations.

At a rubbery $368 billion over three decades (closer to half a trillion would be a safe bet) the budget impact is astronomical, but Defence Minister Richard Marles insists, "it is an investment that we cannot afford not to make."

Labor's penchant for big state intervention to build infrastructure usually comes with major political risks. Cost blow-outs, time overruns and failed delivery ordinarily carry career-shortening implications - think school halls, NBN, pink batts.

But this is different. A more hawkish Coalition has given AUKUS a blank cheque. Even better for Albanese is that the domestic political dividends will tend to be frontloaded into this spend-a-thon.

Huge upgrades for submarine and industrial facilities at HMS Stirling, Port Adelaide and probably Port Kembla if it gets the nod. That means jobs, training, facilities, regional renewal.

Will it make us safer? Will it really involve no loss of sovereignty? That's far harder to know.

Mark Kenny is a professor at the ANU Australian Studies Institute and host of the Democracy Sausage podcast.