The visit of Chinese President Hu Jintao to Washington will be a difficult diplomatic encounter. Mr Hu has chosen first to meet the high priests of capitalism at Boeing and Microsoft, where he may find more support than in the US capital during an election year.

There is much frivolous debate over whether this is an “official” visit or a “state” visit. Let us all be clear, this is an “important” visit that will highlight the economic dependence of the two countries and their potential political estrangement. At this time in history there is no more important relationship, and no relationship more vulnerable to avoidable misunderstandings.

Those misunderstandings are more likely to emanate from Congress than the White House. Few would dispute that the Chinese trade surplus with the United States is large and that the semi-fixed exchange rate adopted by Beijing (at about eight yuan to the dollar) probably undervalues the Chinese currency. And yet no sane economist is calling for a sudden, radical revaluation or any immediate float. There are certainly areas, particularly in intellectual property rights, where the Chinese could and should act with more vigour on the letter and the spirit of international rules. China is prospering from a globalisation that brings with it certain obligations to the global community.

But the sort of vigour favoured in Congress is much less appealing. It is the existence of a sizeable trade imbalance that has prompted outcry, not the subtler explanations as to why this state of affairs might occur. In an echo of sentiments expressed against Japan two decades ago, protectionist forces in both parties on Capitol Hill have endorsed measures, such as retaliatory tariffs on Chinese goods, if the yuan is not revalued massively, which could lead only to a cruelly destructive trade war. Congressmen, too, have obligations to the global community.

The economic relationship between the eagle and the dragon is also much more complicated than the critics are prepared to concede. Not only has China exported goods to the US but it has also exported lower prices. The Chinese have bought about $275 billion in US Treasury bonds (despite their indifferent returns), an initiative that has eased pressure on interest rates to the benefit of all in the debt-burdened US.

The ties between Washington and Beijing are more than an exercise in accountancy. The two countries need to co-operate with each other to contain North Korea’s reckless nuclear ambitions as well as agree a response to Iran’s similar adventurism. China is an emerging political superpower as well as an economic powerhouse. In the longer term, the two have many common interests, which short-term political fireworks largely related to mid-term elections this year should not be allowed to obstruct or obscure.

That emerging Chinese role can be seen in the rest of Mr Hu’s itinerary. After the United States, he arrives in Saudi Arabia, Morocco, Nigeria and Kenya. These are neither leading international players nor regional neighbours. George Bush Sr once said that China was “too big to ignore”. It is even bigger in many senses today.

This President could take an important international initiative by inviting Mr Hu to hold three-way talks in Hawaii with the Japanese Prime Minister. That would truly mark a turning point not only in the Pacific, but also in global relations. And Hawaii is a mercifully long way from Capitol Hill.