It is not often that a European statesman accuses a European commissioner of in effect leaving African babies to die, but Nicolas Sarkozy is no ordinary statesman. The French President has accused Peter Mandelson, the EU Commissioner for Trade, of betraying not just French farmers but also African babies in advance of the crucial world trade negotiations which resume in Geneva next week.

His actual words were: "A child dies of starvation every 30 seconds and the Commission wants to reduce European agricultural production by 21% there's only one person who thinks like that and it's Mandelson".

Peter Mandelson responded to this grotesque attack with dignity and restraint. He will have a most difficult task in Geneva and it clearly does not help his preparations when he is so spectacularly undermined by the leader of the country that is currently presiding over the EU. Mandelson has pointed out with cool authority that the EU's negotiating position, while undoubtedly pro-free trade, has been endorsed by all the EU members, including France and Ireland.

Sarkozy was blustering, partly as a result of his fury after the people of Ireland had dared to reject the Lisbon Treaty in their referendum. The Irish vote disrupted all Sarkozy's grandiose plans for France's six-month EU presidency. He flies to Ireland tomorrow, supposedly to find out exactly what the Irish complaints are - although he has already announced that Irish farmers voted against the treaty because they were opposed to Mandelson's approach to the forthcoming trade talks. I suspect that in Ireland Sarkozy will do more talking than listening, and will leave the country none the wiser.

The irony is that Mandelson and Sarkozy are each key representatives of the European elite. They are almost the same age; each is very clever and each is reputed to be vain. But there the similarities end. Mandelson has worked quietly and effectively as the Trade Commissioner and he is an exemplary Eurocrat. He is a fastidious man, he is good on detail, and he is gay. Sarkozy is showy and seems to have a very short attention span. He is flashily heterosexual; after two earlier marriages, he took time off from his whirlwind leadership of France to marry the glamorous celebrity supermodel Carla Bruni earlier this year.

Sympathetic observers describe him as a man in a hurry; more harsh commentators reckon he is out of control. France's most impressive newspaper, Le Monde, has expressed itself bewildered and confused by his approach to government. He has presided over breathtaking shifts in French foreign policy. Under him, France is now sympathetic to the US, a friend of Israel and pro-Nato.

His most extraordinary initiative is to be found in what he first called the "Union of the Mediterranean", although - significantly - it is now being called the "Union for the Mediterranean". This peculiar body, due to be formally launched this weekend, was originally conceived by Sarkozy as a sop to the Turks for not getting into the EU. Then he refined his notion; what is now proposed is a loose alliance of all the countries around the Mediterranean Sea. In many ways this is a good idea; if the Mediterranean Union takes off, it could be a useful forum for dealing with issues of terrorism and immigration. The French, like the other EU nations that border the Mediterranean, have huge problems with illegal immigration and linked difficulties with North African countries refusing to accept the illegal immigrants they expel.

Sarkozy's leadership style seems to involve scribbling on the back of an envelope with one hand while shooting from the hip with the other. The man clearly has considerable entertainment value (when you compare him, for example, to our own leader). Whether he is a responsible statesman is another matter entirely.

To return to next week's world trade talks in Geneva: their importance can hardly be overestimated. This will not be a quick summit for posturing and showboating, like the G8 jamboree that has just concluded in Japan. The World Trade Organisation is one of the most important and powerful organisations in the world, and one of the least publicised. It can overrule sovereign states; it can overrule the EU.

The last round of WTO talks broke down in 2006. This time there is no room for failure. The three key questions will be: can the really poor countries of the world genuinely benefit from trade liberalisation? Are the emerging economic superpowers, such as Brazil and China, ready to ease the import of sophisticated and specialised manufactured goods? And will the EU at last allow the import of more agricultural goods from poor countries?

Sarko would be well advised to leave the hard negotiating to Mandy.