Barack Obama Emphasises Shared Responsibility in Strasbourg Speech

"Bonne après-midi," Barack Obama said. Two simple words uttered in French and the sports hall erupted in a riot of applause, whooping, and the flashing of mobile phone cameras.

Strasbourg, a French city on the Rhine that used to be German, had never seen anything like it - the US president, the political phenomenon of the age, pacing the stage like a stand-up comedian.

The speech was both sweet and steely, the mastery of the audience and the event complete. "You can speak French or German, but my French and German are terrible," he quipped.

The mainly teenage crowd - 4,000 strong - hummed with happiness. The warm-up act was a girl with an acoustic guitar crooning: "He's got the whole world in his hands." That didn't sound so ridiculous. Obama's speech to a select audience of French and German school students was an exercise in seduction, seriousness and substance. He flattered, warned, listened, and led.

"It is a revolutionary world we live in," he told the hall. He quoted the late Robert Kennedy. "Thus it is young people who must take the lead." Cue standing ovation. Never had they had a politician making them feel so good.

He wanted a nuclear-free world, to banish poverty, to sort out global warming, to get out of Afghanistan (eventually). And he missed the privacy of being able to sit anonymously in a café.

Obama's two big themes were a new age of responsible politics and the reinvention of transatlantic bonds. On both topics he had strong words for his predecessors.

The "reckless speculation of bankers" had caused havoc, the US had often behaved arrogantly towards Europe, "been dismissive, even derisive", while the Europeans had a bad habit of blaming the US for the world's wrongs.

"There's plenty of blame to go around for what has happened. The United States certainly shares the blame ... We've just emerged from an era marked by irresponsibility". But the 18th century values of the French and American revolutions endured, continued to resonate and confer "moral authority" on both countries. And America now needed Europe if the forces of progress were to prevail. "America is changing. But it can't be America alone that changes," Obama declared. "I come to Europe to renew our partnership ... America cannot confront the challenges of this century alone."

There was a warning as well as an offer contained in that message.

The Europeans might be friends and allies, but they also had to "bear their fair share of the burden". Most of all, the barbed signals were directed at European governments reluctant to pull their weight on what the Obama administration has identified as its sorest foreign policy problem: Afghanistan.

"I understand this war has been long," he said. "I understand some question why. What does this mean? What's the purpose? I understand there's doubt about this war in Europe."

But America and Europe "didn't choose to fight this war". "We have no interest in occupying Afghanistan."

And if the new generation of leaders he embodies, the new idealism, and the new fight for progress needed to act now on climate change, on clearing up the financial and economic mess left by his predecessors, and all the other mega-problems, it also had to face up to "one of our central tests", the dangers posed by extremism and terrorism.

Implicit in the speech was the warning that if Europe does not step up to the plate alongside the US in Afghanistan and Pakistan, it will wreck the chance for a fresh start with Washington. And anyway, he declared twice yesterday, Islamist extremism was probably a bigger threat to Europe than to America.

"The terrorists are still plotting. If there's another al-Qaida attack, it's just as likely if not more so that it will be in Europe. This is a mission that tests whether nations can come together in the interests of common security."

Obama fielded a bunch of questions from the students, acting as his own master of ceremonies, teasing and joking before switching tone.

Then he dashed off to Baden-Baden to open Nato's 60th birthday bash. The students were beaming, having just experienced something very rare these days - being inspired by a politician.