Olof Pulme, as prime minister of Sweden, made himself a spokesman for the international liberal and social democratic tradition. He took the view that Sweden's responsibilities in the world required it constantly to press more powerful countries toward arms control, and to press the rich countries toward greater generosity to the poor. Mr. Palme always had an opinion, vigorously expressed -- frequently exasperating to Americans, sometimes a bit pollyannaish, always engaged with the great questions.

His career as a politician breaks into two parts, the years before he lost office in 1976 and the years after he triumphantly returned in 1982. In the earlier period he was one of the most prominent and unremitting of the many critics abroad of this country's part in the Vietnam war. He was also one of Europe's most prominent spokesmen for the ideals of the welfare state. On both subjects he spoke for authentic Swedish traditions. A small nation that had managed to stay out of every war since the defeat of Napoleon, Mr. Palme's Sweden often addressed its neighbors and friends in terms that seemed to them priggish, but the depth of his feelings was genuine. As for the welfare state, it is no doubt easier to construct in a small, very wealthy and highly homogeneous country -- but, he would have argued, all the more reason for Sweden to set a standard for the world.

In his second term as prime minister, after 1982, he was less exuberant and perhaps less audible. Circumstances had changed. Tensions had risen between the two great powers, and the Russians began routinely harassing Sweden with their submarines. Mr. Palme was no pacifist, as he demonstrated when he warned the Soviets that his navy would attack any foreign subs in Swedish waters. In a time of little economic growth and much use of the word austerity, the welfare state was on the defensive. But he knew that both countries and ideas need their defenders.

The only truly un-Swedish and uncharacteristic thing about his life was the ending of it. He was shot by an assassin on the street -- for what reason, we do not know at this writing. He was one of the people who set the terms of debate of his times, and he did it with a verve that makes his death doubly shocking.