When relationships prove to be a headache

Mr Rudd has worked in China and speaks fluent Putonghua. He said last week that while he supports closer defence and strategic ties between Australia and Japan, he doesn't think Mr Howard should have signed a formal security declaration.

"Given [Australia's] current strategic circumstances, I don't believe we should now be moving down the path of a formal defence pact between our two countries. To do so at this stage may unnecessarily tie our security interests to the vicissitudes of an unknown security policy future in Northeast Asia," Mr Rudd said.

What he was really saying is that this new security pact might prove a headache for a future Australian government if tensions between Japan and China, and potentially South Korea, require Australia to take a firm stand on one side or the other.

Mr Howard says such fears are not valid. Australia has a good relationship with China, he says, and he doesn't "believe for a moment" that signing a security declaration with Japan will damage Australia's relationship with China.

Mr Howard's sanguine view has received support from Shi Yinhong , professor of international affairs at the People's University in Beijing. Professor Shi says that "normal relations" between Australia and China will continue, despite Beijing's displeasure at Australia and Japan's actions.

There would be enormous economic and strategic implications for a middle-ranking power like Australia alienating a rising giant like China. So it seems unlikely that Mr Howard would have consented to the agreement with Japan unless he knew that Beijing - despite some public huffing and puffing - wouldn't make life difficult for Australia.

But who can tell what the future will bring, particularly if Japan pursues a more assertive - perhaps even aggressive - role in the region, seriously unsettling Beijing. Such a development cannot be written off as mere fantasy.

It could present Australia with a genuine headache if Tokyo, citing the security agreement between the two countries, were to look to Canberra for material support.