In 1989, there was a great moment of human liberation - the collapse of communism - that also had dramatic implications for Nato. America's military presence was no longer needed in Europe to defend against the Soviet Union. Europe's states faced no threat of outside aggression and were able to meet any remaining security needs. But the transatlantic security alliance's apparatchiks thought otherwise. Nato was a means to an end. Now it became the end. Desperate policymakers began proposing new tasks, such as fighting the illicit drug trade. Today, the continent's greatest security problem is terrorism, but Nato provides little aid. Nevertheless, the Europeans continue to rely on Washington for their defence. Last year, the combined military expenditure of Europe's 24 members, which has a greater combined gross domestic product and population than America, was US$212 billion, little more than a third of the US outlay. Thus, the US should go home. America and the Europeans can continue to co-operate where their interests coincide. Indeed, Europe's most valuable military support for America, from Britain in Iraq, has come from outside Nato. American disengagement has become more necessary with rising tensions between Estonia and Russia. Outside observers long predicted the problems. The controversy involves Estonia's decision to remove a bronze statue of a soldier symbolising the Soviet 'liberation' of the nation from the Nazis. Despite the heroic resistance of Soviets to the Nazis, for many, Stalin was as much a tyrant as Hitler. Thus, the statue was seen more as a symbol of occupation than liberation. But Moscow objected to its removal, launching cyber-attacks against Estonian government websites and interrupting coal, petrol and fuel oil supplies. Estonia is a member of Nato, which forces the US to back it. Through Nato, Washington has committed to go to war against Moscow to defend Estonia. Issuing military guarantees could cost the US dearly. Although Estonia is an attractive friend, it is irrelevant to US security. Moscow, in contrast, matters more. Russia remains the only country with the ability to annihilate American society. In effect, the US is turning the decision about war and peace over to a small, nationalistic country with abundant grievances against a large, nuclear-armed neighbour. Doing so endangers America and its allies. Washington is risking much for no cause. The US should rethink its approach to Europe and Russia. The Europeans are good friends, but they do not need US defence. Washington should make better relations with Moscow a priority, but success is more likely to be achieved through quiet diplomacy than hypocritical public incantations. The dispute between Estonia and Moscow will not be the last international spat between Russia and its neighbours. Washington should ensure that next time America and, ultimately, its friends are not caught in the middle. Doug Bandow is a former special assistant to US president Ronald Reagan