FLANKED by Australia's senior soldiers, Kevin Rudd, the prime minister, stood on a navy frigate in Sydney Harbour on May 2nd and talked of likely future tensions in Asia and the Pacific. He was launching Australia's first defence white paper in almost a decade. The show of naval muscle was calculated. His government plans a military build-up over the next 20 years as a hedge against the tensions, which it worries are most likely to come from China.

There will be only a modest rise in the number of military personnel, of about 3,000 to 57,000. But the navy and air force will get the hardware to build what the paper calls a “heavier and more potent maritime force”. The submarine fleet will be replaced and doubled in size to 12. There will be a new fleet of 11 frigates and air-warfare destroyers, equipped, like the submarines, with cruise missiles. The air force will get about 100 new fighter-bombers. Mr Rudd calls the build-up “the most powerful, integrated and sophisticated set of military capabilities” Australia has had. It is estimated to cost around A$100 billion ($74 billion).

But what is it for? For most of its life, Australia has relied for its security on the naval presence in the Pacific region of first Britain then, since the second world war, America. The paper predicts that China's rise as an economic and military giant could well end all that. It sees China as possibly becoming the world's biggest economy by 2020. That, plus its military modernisation and the testing of America's primacy, could give China's regional neighbours “cause for concern”.

This implies China has now replaced Indonesia as the main strategic threat to Australia. But the paper talks only of a remote but plausible confrontation with “a major-power adversary”. The new hardware's priority will be defending Australia's northern approaches from the Indian Ocean via the Timor Sea to Polynesia. The American alliance will remain pivotal. But Australia will no longer put troops at risk “in distant theatres of war where we have no direct interests” (read Iraq, but perhaps not Afghanistan).

Self-reliance is one thing. How Australia's region will respond to its apparent preoccupation with China as a possible future adversary is another. Mr Rudd seems keen not to let China's status as Australia's biggest trading partner override its security concerns. But Hugh White, a defence analyst, and an author of the last white paper in 2000, worries that this one lacks answers on how this can be achieved. “It's reluctant to tell Australians that we have to think seriously about living in an Asia that will be very different from anything we have known,” he says.