THE ESCAPE of the SS colonel from his hospital bed in Rome last week has its grotesque aspects. His wife, described as "robust," apparently carted him out in a large piece of luggage. How she then got him across at least two international borders, on their way back to West Germany, has yet to be explained. Inevitably it raises ugly questions of collusion. West Ferman officials immediately noted that, whether the colonel had entered the country illegally or not, he would not be returned to Rome because German law does not permit extradition.

The case is a lens through which you can perceive a good deal about the present state of Western Europe.It needs to be said, most emphatically, that it does not imply and lingering sympathy within the West German government for Nazis. For three decades, with great moral stamina and notable sucess, the Germans have prosecuted the endless lists of war crimes and criminals. On that central issue there has never been any wavering. The present incident appears only to reflect the lesser failing of sentimentality.

The colonel is an old man, dying of stomach cancer. Why keep him in jail? Why not let him go home to die in peace? Similar questions have been asked, and not only by Germans, in behalf of other aging war criminals over the years.

But the crime was in Italy, and the question of clemency was up to the Italians. A year ago an Italian court moved in that direction, but the public response was a wave of street demonstrations that forced a reversal. Would you call the Italians vindictive? Consider who the colonel was and what he had done.

His name was Herbert Kappler, and he was the SS commander in Rome in early 1944 as the Allied armies closed on the city and the Italian partisans harried the Germans from the rear. In one attack, partisans killed 33 German soldiers. Col. Kappler seized 335 Italians at random, most of them civilans, and executed them. The shooting of civilian hostages is an unspeakable pratice. For the SS, it was a routine method of government. There are certain crimes in which civilized people do not let bygones be bygones. There is a duty to remember. If a man murders 335 hostages - a man, moreover, who is neither deranged nor stupid - what is the proper sentence? War is an extenuating circumstance, but extenuation does not reach as far as the Roman caves where those hostages died.

For Italians, Col. Kappler's escape is doubly enraging because it suggests official incompetence in holding the prisoner and national impotence in seeking his return. The effect on relations between the two countries was predictable. A meeting scheduled Friday between the heads of the two governments was precipitately cancelled to avoid making bad matters worse.

As for Col. Kappler, he appears to be a man destined to leave a trail of damage for his country, one way or another, as long as he draws breath.