Ernest Bevin, described the treaty that established Nato, as “an endeavour to express on paper the underlying determination to preserve our way of life”. The former Foreign Secretary was right. The alliance has proved to be the most successful liberation movement in history.

That record was besmirched yesterday. Nato members, meeting in Bucharest, barred Georgia and Ukraine from the first stages of joining the alliance. It is a huge diplomatic success for President Putin. Ukraine and Georgia received support from the US, Canada and the nations of eastern and central Europe. There is no indication that Bevin's successors have any notion of the defeat inflicted on the cause of liberal democracy.

Defenders of Mr Putin's obduracy point to “legitimate grievances” that Nato's enlargement aggravates. Yet for two decades Nato has emphasised pacific intent, while Russia has become only more aggressive and threatening. On first meeting Mr Putin, President Bush gushed: “I looked the man in the eye. I was able to get a sense of his soul.” Yet since 9/11, no amount of brutality and authoritarianism on Putin's part has dissuaded Western governments from treating him as a valued ally in the struggle against Islamist terrorism.

There is no reason we should accede to Russia's demands and much justification for ostentatiously flouting them. Mr Putin has few talents on the international stage save bluster and obstructionism. Consider his crude meddling in the Ukrainian presidential election; his economic blockade of Georgia, and his posturing over its would-be breakaway regions of Abkhazia and South Ossetia; his malign encouragement of Iran's nuclear deception; his unilateral overtures to Hamas, nicely designed to sabotage Western efforts at Middle East diplomacy. The hostility is calculated, not reactive.

But the reasons for deploring Nato's decision are not only negative. The coloured revolutions in Georgia in 2003 (Rose) and Ukraine in 2004 (Orange) marked the failure of the Kremlin's dealings with the former Soviet republics. Mr Putin was on the side of the corrupt administrations that popular pressure defeated.

The integration of these states into Nato is not only about security. It symbolises, and consolidates, democratic advance. Mr Putin is a ballot-rigging autocrat whose natural allies are those, such as the Uzbek dictator Islam Karimov, for whom the abuse of human rights is an end in itself. Any diplomatic posture adopted by Nato governments will be taken as provocative by Mr Putin. We might as well therefore do the right thing, not least by those who have to live alongside him.

Oliver Kamm is author of Anti-Totalitarianism: The Left-wing Case for a Neoconservative Foreign Policy

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