Burma visit is not just about trade. The President's aim is to counter the challenge of China

The way senior US officials have been talking, one might think Washington had just discovered this strange new world called "Asia". In reality, since the end of the Second World War, the US has predominantly been an Asia-Pacific power that has worked to make binding relationships with key players in the region. But the choice of President Obama's first foreign trip since re-election and the repeated – if inelegant – talk of the "Asian pivot" underscores the ongoing recognition of the region's mounting importance and of both the opportunities and challenges it presents, most obviously in China.

"Why is the American President spending all this time in Asia so soon after winning re-election?" Secretary of State Hillary Clinton said in Singapore last week. "Because so much of the history of the 21st century is being written here." Yesterday Mr Obama met the Thai Prime Minister, Yingluck Shinawatra, whose government is considering joining the Trans-Pacific Partnership (TPP).

He will meet South-east Asian leaders in Cambodia. Ben Rhodes, the Deputy US National Security Adviser, told reporters travelling to Thailand with Mr Obama: "We felt it was very important to begin this trip by visiting a US ally. Allies are the cornerstone of our rebalancing effort in Asia."

The TPP agreement will focus on trade as the US looks not only for new markets, but to counter the rising influence of China. The US is Thailand's third-biggest trading partner, behind China and Japan. But the talks will not just be about trade. China is involved in angry disputes with Japan, the Philippines and Vietnam over contested islands. These clashes could undermine any new trade agreements.