The murder of Alexander Litvinenko is an irresistible story, but it shouldn't have taken the death of one man to alert us to the fact that we have a serious problem with Putin's Russia. Whether Litvinenko's poisoning was ordered by the Kremlin or not, it has been obvious for some time that we are dealing with a regime whose contempt for democracy and human rights at home is matched by an increasingly aggressive and unilateralist approach to foreign policy.

Offstage from last week's spy drama, a storm was brewing with far more profound long-term implications for our relations with Russia. It was brought to a head by Poland's decision to veto negotiations over a new cooperation agreement between the EU and Russia. Poland's grievances are perfectly valid. Russia is not only violating an agreement on energy by using gas supplies as a political weapon, but it has banned Polish meat imports in an act of pure diplomatic spite. Russia has now threatened to extend that ban to the whole of the EU from January.

Trade embargoes imposed for bogus health-and-safety reasons are fast becoming a favourite foreign-policy weapon for Russia. Georgia and Moldova have been similarly targeted. But the coercive use of energy policy gives greatest cause for concern. Europe now depends on Russia for 25% of its gas, a figure set to rise to 70% by 2020, at a time when Russian behaviour is becoming more belligerent.

Optimists point out that even during the Soviet era Russia remained a reliable energy supplier. But this ignores one crucial difference. Post-Yalta, the Soviet Union's main objective was to maintain the status quo and preserve its sprawling empire with subsidies and military force. For this it needed to trade with the west; energy for hard currency. But just as the west is no longer the only potential customer, Russia is no longer a status-quo power. It is a revisionist power whose president publicly laments the collapse of the Soviet empire and seeks to restore its dominant position by fair means or foul. Energy is now its instrument of choice.

It is a cardinal principle of Putin's hard nationalist outlook that the countries on Russia's borders are not entitled to choose their political destinies. That's why Russia reacted so furiously to the rose and orange revolutions. In this respect, Russo-European tensions reflect a fundamental clash of strategic cultures. While modern Europe has embraced voluntary integration and the rule of international law, Putin's foreign policy belongs to an older European tradition with its "spheres of influence" and great-power rivalries. To the extent that the EU provides a pole of attraction for parts of the former Soviet Union that wish to escape this Hobbesian universe, Putin has come to see it as a geopolitical rival.

Russia's role as an increasingly dominant energy supplier is sometimes said to be an example of "soft power". But there is nothing soft about cutting off gas supplies to a country such as Ukraine in the dead of winter. It is an illegitimate instrument of intimidation. Beyond Russia's "near abroad", Putin combines measures to increase Europe's dependency on Russian supplies with reminders that Asia provides an alternative outlet. The idea is that Europe should take the hint and avoid disagreement with Moscow - a form of diplomatic self-policing known as "Finlandisation".

European diplomacy should be aimed at presenting Russian policy makers with a clear choice. They can have a constructive and profitable energy partnership on fair commercial terms, provided they renounce monopolistic practices and abandon the use of energy supplies for geopolitical advantage. That means living up to their obligations under the energy charter treaty and ending their pipeline monopoly by signing the transit protocol. Otherwise Europe will single-mindedly pursue a policy of energy independence by diversifying its energy mix, improving efficiency and building the supply infrastructure needed to access non-Russian sources.

There is no appetite for cold-war revivalism in Europe, but we will not develop an effective policy towards Russia until we get over the post-cold-war cringe of believing there is something shameful about standing up to a leader like Putin. It is not "Russophobic" to oppose the hegemonic ambitions of the Kremlin any more than it is "anti-American" to object to the unipolar pretensions of neoconservative policy makers in Washington. Both reflect a mindset that reveres power politics and rejects sovereign equality as the basis for international relations. That's not the European way, and it's time we made that clear.

· David Clark is chairman of the Russia Foundation and a former government adviser.

Dkclark@aol.com