THE REMARKABLE THING about the new Italian government is that it's not headed by a Christian Democrat. Giovanni Spadolini is the first prime minister in 36 years and 41 cabinets to belong to another party. He's a Republican and, since the Republicans are a small and cautious operation, his government presumably indicates a transition to something else.To what. That probably depends on the economic pressures that, one by one, are pushing the politics of most of the European countries off their accustomed tracks.

At the end of World War II, each of the three defeated powers put its political life in a sort of informal trusteeship, under a party of the democratic right, and went about the more pressing business of getting rich. The trusteeship eroded most rapidly in West Germany. There the Social Democrats dropped their Marxist and radical allegiance in the late 1950s, won strength in the center, and evolved into the party that has been in power for the past seven years. In Japan, the party of the center-right turned into an umbrella under which a great variety of factions compete.

The Italian case was somewhere between the other two. The Italian Christian Democratic Party was as intricate a family of factions as its Japanese counterpart, but never developed anything like the forceful Japanese bureaucracy to carry out policy. In Italy the principal opposition was a Communist Party that, unlike the German Socialists, never cast off the Marxist tradition. Now the Christian Democrats -- in power far too long, ingrown and narrow in their perspective -- seem to have lost their dominance. They weren't pushed; they gradually slipped.

It's time. Italian politics has been in a state of paralysis for years. One measure is the failure of successive cabinets to cope, or even try very hard to cope, with inflation that is now well over 20 percent a year. Another measure is the poverty of the public services, beginning with education and health, and the government's inability to provide the social infrastructure needed by the industrial society that Italy had become.

Mr. Spadolini, the Republican, serves the useful purpose of signaling change without immediately threatening anyone. But the process isn't going to stop with him.It seems to be pointing in the direction of the small but ambitious Socialist Party.

The Socialist victories in France, and the appearance of four Communists in minor cabinet seats there, have given respectability to the idea of government of the left. The Italians can now afford to carry on their own experiments in that direction without isolating themselves from the rest of Europe. The Spadolini government respresents the first gingerly step.