When 400,000 peaceful marchers took to the streets of Florence over the weekend in protest against the prospect of war with Iraq, they sent an important message to the governments both of Europe and the US: remember Vietnam.Whatever the merits of the case against Saddam Hussein, no matter the unanimity of the UN Security Council, there is a large constituency that remains unpersuaded and is mobilising hard. And it is strikingly broader than that which opposed the Afghan war.
The movement's seriousness of purpose, and increasing international connections, were reflected in the 40,000 activists from 475 anti-establishment groups in 100 countries, Ireland included, who gathered in the city at the European Social Forum in the days before the march. They discussed some 400 topics that ranged from globalisation and militarism, to vegetarianism, migrant rights, democratic participation in the EU, and development in Africa, under the general theme "Another Europe is possible".
It would be easy, but wrong, to dismiss the gathering as just "the usual suspects". In the wake of the Seattle WTO summit in 2000 the movement against capitalism and globalisation has shown remarkable resilience, as the hosts of not a few summits have discovered. Emerging in the ideological vacuum created by the demise of the old Communist Parties and the perceived capitulation of New Labour parties to the system, infected by environmentalism, the new movement is an extraordinary amalgam that draws from greens, Trotskyists, anarchists, development and peace campaigners, and others - including even the churches.
Deeply incoherent and contradictory, it is a movement that knows clearly what it is against but has failed to articulate an alternative, a movement that one British supporter, George Monbiot argues, must move now from "opposition to proposition". At that stage it may well, like the old left, split into myriad factions. But it is an alienated cry of rage from decent young people at real global injustice and the inability of a system of plenty to share either wealth or power that must be heard and engaged with.
The British Prime Minister, Mr Blair, tried to do so at the weekend. "Globalisation is a fact, not a choice," he argued. "That doesn't mean we have to espouse ultra-liberal or Thatcherite policies." But voices of the international establishment will have to to do far more to convince young people that they share their concerns. They ignore them at their peril.