THE RED BRIGADES in Italy represent a psychological condition in search of a political cause. The quintessential terrorist organization, it has now kidnapped an American soldier, Brig. Gen. James L. Dozier, to protest, as it claims, the American military occupation of Italy.

The protest comes a bit late, but for the Red Brigades' purposes, that's just as well. The American military occupation of Italy at the end of World War II was decidedly popular among Italians who lived in the northeastern part of the country, where Gen. Dozier was seized last Thursday. As the German armies collapsed in early 1945, Marshal Tito's Yugoslav partisans swept across the border into Italy with the clear intention of taking permanent possession of a large piece of it. Only under the threat of force by the Americans and British did Tito reluctantly withdraw to a compromise line. An American infantry division was posted on that line as a guarantee to the defenseless Italians, and there it remained until the final peace treaty was signed two years later. That was the substance of the American occupation. The Brigades' use of the term is presumably a hyperbolic reference to Italy's current membership in NATO, in the logistical apparatus of which Gen. Dozier serves. Here as always the Brigades are addressing an audience without much of a memory--and no memory at all of the real occupation, or the real reason for it.

Perhaps the Brigades will try to bargain with the general's life, offering his safe return for various political concessions. Unfortunately, the right response is a flat refusal. That was the position taken by the Italian government three years ago when one of the country's leading political figures, former premier Aldo Moro, was seized by the Red Brigades. No different answer is permissible in the case of an American soldier.

Hunting terrorists is always extremely difficult in a country that operates under the rule of law. But it's worth noting that the Italian police and courts have been unusually effective in recent years--more effective than, for example, the authorities pursuing the Weathermen in this country over the past decade. Most of the people involved in the Moro assassination are now in prison, and likely to remain there for quite a long time. The kidnapping of Gen. Dozier is the work of an organization much reduced in membership, on the run, desperate for attention, and now gambling that this shocking assault can restore some of its earlier momentum.