By the BBC's Martin Rosenbaum
The port of Immingham rises out of the mud of the Humber estuary, a massive modern construction of cranes and docks against the grey waters where the sea meets the river.
Immingham is hardly a household name in Britain, and yet it is as vital a part of the heartbeat of the United Kingdom as Heathrow airport or our motorway network.
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The enormous volume of international trade coming in and out of Immingham makes it a good place to start thinking about Britain's role in the world now.
Almost 10% of our total trade goes through this one British port and it's mostly to and from Europe.
Half Britain's trade now is with the European Union.
Only about a sixth of our trade is with the United States.
Britain for years has faced two ways.
We are drawn by the United States and our English-speaking former Empire.
We are also powerfully pulled towards Europe.
Britain has been profoundly influenced by American culture and ideas - everything from rock'n'roll to Budweiser beer - but also by our obvious geographic, economic and political links with the continent of Europe.
Britain's role and where we fit into the world is the new Battle of Britain for the 21st century, at the heart of our noisiest political debate
Yet this spring of 2003, Britain has begun to make some fateful historical choices.
We have lined up with the United States yet again in a foreign war which the governments in Washington and London see as rooted in our common values - democracy, freedom, standing up to dictators and terrorists, a notion of world peace and of personal liberty.
And Britain is also on the point of making a decision about the euro - or perhaps we will decide not to decide on the euro, depending on Gordon Brown and his five tests.
Either way, Britain's role and where we fit into the world is the new Battle of Britain for the 21st century, at the heart of our noisiest political debate.
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How American are we in the way we think about work, money, taxes, the wider economy, the use of power?
Do we still see Americans as our kith and kin, part of an intimately bound English speaking world?
Or are some of us becoming increasingly anti-American, filled with a caricature view of Americans as arrogant, ignorant and yet inexplicably successful?
How European is Britain in our cultural identity, our welfare state, our dislike of many American values, and the obvious fact that British cities look and feel much more European than the skyscraper monsters of north America?
Trade is only one indicator of which way Britain faces economically.
When it comes to where British people and British companies put their money through investment, all that is weighted towards the United States.
Companies associated with the transatlantic business group British American Business Inc. say - in the words of international corporate lawyer Daniel Rosenberg - that the British are 'much closer to the Americans in the way business is done'.
British legal documents for example - like those in the United States - tend to be long and detailed.
In the rest of Europe business deals are expressed in shorter legal documents which rely much more on the general law.
Many British businesses feel, in that awkward American phrase, 'more comfortable' dealing in the American system than the French or Italian legal system, over and above the obvious ease with which the British and Americans speak a common language.
But do the British think about business much more like Americans?
The Conservative politician John Redwood insists we do.
The British, he argues, hate red tape, high taxes, and being bossed around even by a well-meaning big government.
All very American. But others, like the author Will Hutton, argue that the British believe in a very European way that businesses are more than just machines to print money.
So at a time when Gordon Brown is about to give his opinion on his five tests for joining the euro, 'Which Way Are We Facing?' explores Britain's extraordinary links with two continents.
Tony Blair asserts that Britain can be a 'bridge' between Europe and the United States.
But from Nato's secretary general George Robertson - who admits his job is often to bridge differences between Europe and America - we hear how being as he puts it, in mid-Atlantic, can be cold and wet and very, very lonely.
'Which Way Are We Facing?' starts at 2000 BST on Monday, 5 May, on Radio 4, and is presented by Gavin Esler.