Being able to claim friendship with the United States, our great and powerful ally, has been a prerequisite for successful Australian political leaders since World War II.

Only the Labor leaders Evatt and Calwell in the 1950s and 1960s dared to present views different from the mainstream of American political opinion — and they did not win an election between them in nearly 20 years. Whitlam was a tardy opponent of the Vietnam War with his criticisms coinciding with, but not leading, significant opposition within the US.

From peace in Vietnam until now, there has been virtually no occasion when both sides of Australian politics have not been in broad agreement with the views of the incumbent US administration, which were in turn broadly similar to those of the US opposition party.

True, Mark Latham had a brief flirtation with daring to be different by declaring President George Bush to be a danger to the world and promising a quick withdrawal of Australian troops from Iraq. That put him in the Evatt and Calwell category, before he spent several futile months trying to pretend that he wasn’t anti-US after all as he masterminded Labor to an ignominious defeat.

But in the two years since our last election there has been a significant change in the US environment – and now Kevin Rudd finds himself in a similar position to Whitlam in that there is no longer unanimity among the two major American political parties as to what should be done about a foreign war. Significant sections of US opinion, spread across both parties, are now advocating withdrawal from Iraq as the right thing to do. What was an heretical view by Latham in Canberra is now mainstream in Washington.

The disappearance of a foreign policy consensus in the US centre makes things much more difficult in the Australian satellite. How to devise a policy where you can be seen as a loyal friend, irrespective of which side wins the American debate?

John Howard at the weekend abandoned the attempt and decided that if picking sides was good enough for Evatt, Calwell and Latham, it was good enough for him. Instead of retreating into cautious moderation, he attacked the Democrat presidential candidate Barack Obama for calling on the US to withdraw its troops to Iraq by March next year.

Kevin Rudd, meanwhile, is clearly very comfortable when the discussions turns to foreign policy and he has spent this week very effectively talking about the danger of Australia alienating one of the two sides of American politics while not committing himself to endorsing Obama’s view.

Rudd must be unable to believe his luck.