"As the fastest-growing region in the world, no market is more important to our economic future than the Asia Pacific - a region where our exports already support five million American jobs," Obama said.
The Asia-Pacific region produces 60 per cent of the world’s GDP and represents half of world trade.
That means there’s a lot of trade to be done, but at the back of the American collective mind is the threat to US hegemony from the rising giant, China.
So Obama’s Trans-Pacific Partnership, a trade pact whose “broad outlines” were announced on 12 November, would not include China and that’s no coincidence.
“It’s a posse to get China,” according to Sydney Morning Herald editor Peter Hartcher.
On a stopover in Australia, Obama announced the first long-term expansion of US military presence in the region since the Vietnam war – stationing 2,500 troops in Darwin in Australia’s tropical north, looking out onto Indonesia and not so far from the South China Sea.
He also pledged that, despite the US’s debt crisis, there would be no reduction in military spending in the region.
That will “preserve our unique ability to project power”, Obama said.
The Australian visit, during which he apparently got on famously with Prime Minister Julia Gillard, also saw bilateral ties significantly deepened.
Another key factor of Obama’s strategy is to win allies among Asian countries that might feel threatened by China.
So US diplomats have been taking a great deal of interest in the South China Sea. China and Taiwan both claim all of the sea. Other south-east Asian countries claim parts of it and Vietnam and the Philippines have accused Chinese forces of an increasingly aggressive attitude there.
One-third of the world’s maritime trade and half its traffic in oil and gas takes place in the region and major petroleum and other mineral deposits are believed to lie, untapped, beneath the seabed.
"The United States has an interest in the freedom of navigation, the free flow of commerce, a peaceful resolution of disputes [but] we don't have a claim, we don't take sides in the claims," US National Security Advisor Tom Donilon said on the sidelines of the Association of South-east Asian Nations (Asean) meeting in Bali.
But Obama had a “very robust conversation on maritime security in the South China Sea” when he held an unscheduled meeting with Chinese Prime Minister Wen Jiabao in Bali, an anonymous US official told the AFP news agency, adding that Wen “started off maybe a little grouchy” but was “by and large […] very measured”.
Much of Washington’s sniping over China’s human rights record and its periodic concern over apparent military threats to Taiwan might also be motivated more by political considerations than pure American idealism.
Obama’s final coup de théatre in Asia was to announce that Secretary of State Hillary Clinton would soon be visiting Myanmar.
This is supposedly to encourage the moves to reform of the country’s new government but, again, China features in the calculations.
Beijing has been Yangon’s only real ally as it came under pressure from Europe and the US to open up to the West and stop repression of Aung San Suu Kyi’s National League for Democracy and other political or ethnic opposition.
But the new government has scrapped a project to construct a megadam, which would have sent much-needed power to China and shows signs of wanting to broaden its circle of diplomatic acquaintances and the US clearly wants to encourage the process.
So no wonder the official Xinhua news agency accused the US of a “Cold War mentality” and engaging with Asian nations in a “self-assertive way”, advising it to “guard against sparking disputes and encroaching on others’ interests”.
In reality the US has long been involved in the Pacific region, even if one disregards the unfortunate Vietnam episode.
Before he became president in 1909, William Taft was governor of the Philippines, wrested from Spanish control in the war that started the US’s ascendancy to superpower status.
And Darwin served as the base for General Douglas MacArthur in the Asia-Pacific theatre of World War II when the US defeated Japan’s attempt to dominate the region.
But the reorientation of the world economy that was already underway in the 20th century seems irreversible today.
Obama has rather optimistically declared that the conflicts in the Middle East and Afghanistan are drawing to a close and the US’s attitude to Europe now seems to be one of damage limitation in the eurozone crisis, leaving him relatively free to concentrate on Asia.
With massive holding in US government bonds and exports to the US that guarantee cheap goods for American consumers and retail and distribution jobs for American workers, China has to be handled with care.
But its 2030 GDP is predicted to be 25 per cent higher than the US’s, it is investing in Africa, Europe, Latin America – everywhere, in fact – and it is trading across the world. With economic clout comes influence.
After the cloudy illusions of the end of history dispersed, US strategy makers had to face up to the historical fact that all empires come to an end, although no one knows for sure when the US will finally lost its ability to project power.
Will Washington bow out gracefully and accept playing second fiddle, as Britain did after World War II?
Or will the attempts to contain China at some point turn into open conflict?