Nothing about this week's Nato summit will help President Bush in his quest to improve his legacy. European members of the alliance will almost entirely rebuff today his call for more help in Afghanistan (and France, which had offered more troops last week, has already appeared to cut the number by half).

Bush is also picking a second fight he looks likely to lose — with Germany, France and Russia — in his blunt call for Nato expansion to Georgia and Ukraine. Even if he fails to add this to his legacy, he is in the right to pull as many as he can into the club of the West.

That is all the more so for Russia's creeping influence on its former satellites, the menacing subtext of this summit. Indeed, Bush's most valuable contribution this week will be invisible in the history books, but it is the task of standing up to Russia without provoking an outright collision. The worrying theme of the Bucharest gathering is not that the alliance has no purpose, but that its old one of countering Russia is still relevant — and that Western Europe is loath to do much about it.

The choice of the monstrous Ceausescu palace, a hulk of grey concrete looming over the low-built, still-shabby city, is a reminder that the purpose of Nato was to defend European democracy against the threat from the east. Romania's huge delight at hosting an alliance it joined in 2004, after a ten-year campaign, is an endearing testament to the transforming power of such clubs (although it could perhaps have left out of the welcome packs a DVD of a noted film about an illegal abortion).

Nato summits produce good rows, because for all the talk (and the 26-member union is shorter of soldiers than words), they come down to a demand for troops and money. Afghanistan is the worst row for years. As the US began to look up last year from its immersion in Iraq, to notice that Afghanistan was getting worse, it called on Nato members to send more troops, and to release them from “caveats” keeping them back from the fiercest fighting. Its frustration is not with Britain, Canada and the Dutch, which have shared the burden of the fighting. The complaint is directed at other members, including Germany, which has kept its forces in the more peaceful north.

The US is entirely justified in its general gripe that it picks up the vast share of Nato's burden. It carries three quarters of the military burden in Afghanistan (and 85 per cent of the air power). Britain, which as the US's closest ally, accepted the particularly tough mission in the south, fills much of the rest. They are both right to argue that leaving Afghanistan as a failed state is a boon to terrorists.

And yet, other members have a point in arguing that while they were obliged under the Nato charter to come to the US's defence after September 11, 2001, the Afghan mission has transformed unrecognisably into the undefined salvation of one of the world's poorest countries. It seems perverse of the US to censure Germany for not risking its forces — a stance backed by the German public — after half a century of trying to persuade it to excise its military past. But the US should be commended for wanting to bring Ukraine and Georgia within the fold. Russia is steadily trying to win influence again over the former Soviet bloc countries, through low-level threats about gas supplies and trade. Germany's resistance to that enlargement, and its preference for a closer relationship with Russia, will not solve that problem.

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