Sarkozy's warm words mask deep divisions with US

Nicolas Sarkozy has proclaimed a new era in the often troubled relationship between the United States and France, urging Washington to "trust Europe", and throwing his weight behind tough new sanctions to force Iran to halt its uranium enrichment programme.

In an address to the US Congress interrupted only by several standing ovations, the French President spoke in glowing, at times emotional, terms of America and its role in the world, and of France's debt to the US in two world wars and the Cold War that followed.

The atmosphere could not have been further from the frosty chill that prevailed under M. Sarkozy's predecessor, Jacques Chirac, who enraged the Bush administration with his opposition to the Iraq war.

This time, by contrast, Iraq went unmentioned. Instead, the French President delivered a stern warning to Tehran, borrowing the language of President Bush himself. "The prospect of an Iran armed with nuclear weapons is unacceptable," he declared. "No one must doubt our determination."

His words will delight the White House, in a week crucial to its efforts to rebuild ties with the "Old Europe" scornfully dismissed by the former defence secretary Donald Rumsfeld before the 2003 invasion of Iraq. This weekend the German Chancellor, Angela Merkel, the successor to M. Chirac's perceived partner in defiance, Gerhard Schröder, is being accorded the rare honour of a stay at Mr Bush's ranch in Texas.

"We may disagree, but we remain friends," M. Sarkozy said on the first day of his visit, capped by a quasi-state dinner at the White House. He expanded on that theme during his address to the Senate and House of Representatives yesterday.

The US and France were partners, he said. In the fight against terrorism, "America can count on France", and in Afghanistan his country would remain engaged "as long as it takes". He promised co-operation on other Middle East issues, including Lebanon and an Israeli-Palestinian settlement. But however much personal relations at the top have improved, large obstacles stand in the way of rapprochement – above all the enduring unpopularity of Mr Bush in Europe, and his limited remaining time in office. M. Sarkozy and Ms Merkel are well aware how Tony Blair was brought down in large part by his unquestioning support for the US President.

And his warm words mask substantial policy differences. He chided Washington yesterday for backsliding on free trade and its failure to join Europe in the fight against global warming. He also warned about the tumbling dollar. "The dollar cannot remain solely the problem of others," he said. "If we're not careful, monetary disarray could morph into economic war. We would all be its victims."

He did not offer much on a return by France to Nato's integrated military command structure. Nor did he touch upon Turkey, which the US has long lobbied for admission into the EU, a step M. Sarkozy has described as "nonsensical". But for a day, in the balmy atmosphere of his visit, such differences have been forgotten.