In 1920, Winston Churchill's mother held a dinner for M Paul Cambon to celebrate the end of his 20 years as the French ambassador to Britain. One of the guests asked Cambon what he had seen in his two decades in London.

"I have witnessed an English revolution more profound and searching than the French revolution itself," Cambon replied. "The governing class have been almost entirely deprived of political power and to a very large extent of their property and estates; and this has been accomplished almost imperceptibly and without the loss of a single life."

Buried in that answer is a picture of how politics should work. Britain faced an enormous task: to move from an aristocratic political economy to a democratic, industrial one. This transition was made gradually, without convulsion, with both parties playing a role.

This wasn't because the political leaders were so brilliant. They simply responded to a series of immediate problems. Nor was it because they were postpartisan angels. The parties fought vigorously.

It's just that the system worked. Each party took different whacks at pieces of the great national problem, depending on its interests. Opposing parties, when it was their turn in power, quietly consolidated the best of what the other had achieved. Gradually, through constructive competition, the country quarrelled its way forward.

The United Kingdom seems to be in the middle of that sort of constructive quarrel now. Usually when I travel from Washington to Britain I move from less gloom to more gloom. But this time the mood is reversed. The British political system is basically functional while the American system is not.

As the British politician Oliver Letwin has argued, a generation of misrule between 1945 and 1979 left the UK with three large problems: a stifled industrial economy, an overcentralised welfare state and an enervated people, some of whom are locked in cycles of poverty.

By liberating the economy, Margaret Thatcher tackled the first of these problems, and subsequent Labour governments consolidated her gains. Meanwhile, a series of governments have been fitfully tackling problems two and three, reforming the welfare state and energising the populace.

In conversation, the Conservative and Labour leaders are happy to rubbish each other, but what's striking to an outsider is how much their concerns overlap. A series of governments, going all the way back to John Major's administration in the 90s, have tried to decentralise power, come up with new ways to measure government performance, reduce welfare dependency and improve early childhood programmes.

Many of the programmes have failed, but the general direction is clear: the move from a centralised, industrial-era state to a networked, postindustrial one.

The momentum is especially evident just now. David Cameron, the prime minister, is a skilled politician who dominates the scene. His agenda doesn't merely touch his party's hot buttons, but moves in many directions at once.

His austerity programme includes tax increases as well as spending cuts. He's vigorously protecting the foreign aid budget as he cuts almost everywhere else. He has aggressively reformed welfare and education while retreating on health service reform.

By balancing his agenda, by conveying a sense of momentum, by insisting on fiscal responsibility, he's remained popular. His party did well in the recent local elections, even amid the fiscal pain.

Britain is also blessed with a functioning political culture. It is dominated by people who live in London and who have often known each other since prep school. This makes it gossipy and often incestuous.

But the plusses outweigh the minuses. The big newspapers still set the agenda, not cable TV or talk radio. If the quintessential American pol is standing in his sandbox screaming affirmations to members of his own tribe, the quintessential British pol is standing across a table arguing face to face with his opponents.

British leaders and pundits know their counterparts better. They are less likely to get away with distortions and factual howlers. They are less likely to believe the other party is homogeneously evil. They are more likely to learn from a wide range of people. When they do hate, their hatreds are more likely to be personal and less likely to take on the tenor of a holy war.

The British political system gives the majority party much greater power than any party could hope to have in the US, but cultural norms make the political debate less moralistic and less absolutist. The British press also do an amazing job of policing corruption. The media go into a frenzy at the merest whiff of malfeasance. Last week, for example, a minister was pummelled for saying clumsy things about rape.

On Tuesday, as President Barack Obama visits London, we will get a glimpse of the British political culture. We Americans have no right to feel smug or superior.

© 2011 New York Times News Service