PARIS — The Eiffel Tower was illuminated in the blue and gold of the European flag last night in a spectacular start to France’s six-month presidency of the European Union.

But behind the glitter, President Sarkozy inherits a Union in disarray amid fears that he lacks the diplomatic skill for the job.

European leaders know it will take more than a few shows of unity to turn France’s presidency into success, regardless of Mr. Sarkozy’s energy or communication skills.

His first unforeseen stumbling block has come from Ireland, which voted against the “simplified” Lisbon Treaty in a referendum on June 12, throwing the ratification process into chaos.

Last night, in an hour-long televised interview on the state channel, France 3, Mr. Sarkozy said there had been “errors” in building Europe.

“We must therefore profoundly change our way of building Europe,” he said. “Europe worries [its citizens]. Worse, little by little its citizens are wondering whether at the end of the day the national level is not better placed to protect them than on a European level.

“Above all, I think that we must think about how we can make Europe a means to better protect Europeans in their daily lives.”

He stood by his outspoken criticism of the European trade commissioner, Peter Mandelson. “He’s a man of quality, who I respect,” he said. “But nobody will make me accept a cut in farming production on the altar of global liberalism.”

He said he was prepared to consider reducing E.U. farming subsidies, the lion’s share of which go to French farmers “but only if we have price guarantees.”

Responding to claims that he, and French leaders in general, are too arrogant, he tried to be magnanimous: “It’s true, our country was seen sometimes as arrogant. Why? It’s not a question of temperament, it’s because we had a tendency to tell others, ‘Do what you have to do but we won’t do it.'”

That had now changed under his leadership, he said.

He refused to be drawn on whether Ireland should have another vote on the Lisbon Treaty, but said a solution would have to be found by June 2009.

Mr. Sarkozy is intent on pressing ahead with ratification among the other 26 E.U. members, while others argue that it is dead in the water. Mr. Sarkozy will visit Ireland on July 11 to “listen” to politicians in Dublin, who have until October to come up with a contingency plan.