The role of Nato

"I worry a great deal about the alliance evolving into a two-tiered alliance, in which you have some allies willing to fight …

"I worry a great deal about the alliance evolving into a two-tiered alliance, in which you have some allies willing to fight and die to protect people's security and others who are not." So said US defence secretary Robert Gates to the US Senate defence committee this week in a reference to the North Atlantic Treaty Organisation (Nato), the future of which, he stated, was under a cloud.

His remark forms a fitting backdrop to today's meeting of Nato defence ministers in Vilnius, where the alliance's under-resourced Afghanistan operation will top the agenda. In London, Prime Minister Gordon Brown told parliament "we need a proper burden sharing" in Afghanistan after it was announced that the 7,200 British troops there are shortly to rotate but not increase in number. His foreign minister David Miliband then accompanied Dr Condoleezza Rice to Kabul yesterday as a morale-boosting exercise following a disappointing response to US pleas for extra troops to be sent there. In London she sharply reminded Nato member states that the Afghan operation is a counter-insurgency exercise rather than a peacekeeping one.

Mr Gates and Dr Rice are particularly critical of Germany's refusal to commit extra fighting troops to Afghanistan. German public opinion is hostile to that, a phenomenon which also affects other Nato governments in Europe. As a result more of the burden falls on the US, UK, Dutch and Canadians (who have threatened withdrawal). Tension over criticisms by Mr Gates of British and other counter-insurgency tactics in southern Afghanistan is matched by bitterness over what they regard as clumsy and misguided US military tactics, including proposals to spray opium poppy plantations in an effort to reduce this growing revenue stream for the Taliban.

Afghanistan is a microcosm of Nato's wider difficulties over its proper role in the post cold war world. During the 1990s that discussion was delayed by Nato enlargement and the creation of the partnership for peace structures in Europe during the Clinton years. The Bush administration's disregard for Nato and preference for unilateral coalitions of the willing after the 9/11 attacks still rankles with European leaders who now have more appropriate EU military structures to use when required. There is considerable unease about enlarging Nato towards Ukraine and Georgia, for fear of gratuitously offending Russia. Similar factors animate the recent Polish, Czech and Slovak criticisms of the proposed US missile shield against Iranian rockets. Mr Gates's fears about a two-tier alliance should herald a much more thoroughgoing debate about Nato's continuing relevance.