The protest movement of the late 1960s led eventually to the deaths of four students at Kent State University, Ohio, in May 1970. That was not the end of the big demonstrations in that era but there were no more fatal confrontations. Let us hope the same may be said of the movement that has erupted in Western democracies over the past two years.
The death of a 23-year-old protester at the G8 summit in Genoa at the weekend was all too predictable. The paramilitary police conscript who shot Carlo Giuliani was himself aged only 20. The tragedy should cause everybody in this "anti-globalisation" campaign to come to their senses. Whatever the merits of their objections to free trade, multinational capitalism or materialism in general, the cause is not worth any risk to life or limb.
It seems to be essentially a cultural movement, as that of the 1960s was, an inchoate rebellion against the very forces that have made their lives rich and comfortable, though they would not acknowledge that. It is not that they would prefer to be poor and denied the products of commerce; they are not clear about what they want. As in the 1960s, they are more definite about what they are against. Counter-culture is really as far as it goes.
Now it has a martyr, and responsible people on both sides of the argument will take no satisfaction from that.
The leaders of the G8 nations, the world's eight largest economies, have resolved to scale down their gatherings and meet in more out-of-the-way resorts. If the anti-globalisation campaign wants to call that a victory, it can. The avoidance of further injury and death is worth a back-off. And cities such as Genoa should not be asked to suffer destruction and pillage for sake of meetings that could be held in places less convenient for the anti-capitalism crowd.
The World Trade Organisation, having suffered the attentions of the crowd at Seattle, will hold its next ministerial conference in November at Qatar. Knowing the Director-General as we do, New Zealanders might suspect who suggested that venue. At Qatar there will be another attempt to agree on a new round of multilateral trade negotiations. It may fail, as Seattle would have, with no help from hordes of protesters.
The most important international meeting at the weekend was not the gathering in Genoa - the G8 meets regularly and enables the leaders to monitor common concerns but it rarely reaches momentous decisions. The more significant event on Sunday was in Zanzibar, where officials of the world's poorest nations, most of them in Africa, met to develop a common approach to the Qatar conference.
As at Seattle, the first time the least developed countries had formed a concerted view within the World Trade Organisation, the mood at Zanzibar was against a new trade round until the rich nations do a better job of honouring the agreements reached in the Uruguay round eight years ago. It is an entirely justified attitude to take, and one that agricultural exporters such as New Zealand could echo.
It is also an attitude that will be misinterpreted by the rock-throwers in Western capitals, who claim they are on the side of the Third World. They delude themselves. Poor countries have been lining up to join the WTO in recent years because they noticed that trading nations had got richer and those that followed the prescriptions of socialism had not.
Debt relief, assistance against Aids, protection of indigenous knowledge - all of which the anti-globalisation mob endorse - are important to Africa's prospects, but ultimately it is trade that brings sustained wealth.
When Third World leaders see the demonstrations in the streets of North America and Europe, they must shudder. The most likely effect, as the organisers intend, is to make the developed democracies fearful of further trade liberalisation.
To the credit of the representatives of the G8, they kept their resolve at Genoa. They were listening to Zanzibar as well as the mob outside. They resolved to make globalisation work for the world's poor with aid as well as trade. And they reaffirmed which of those is the real key to global prosperity.