Fifteen innocents died in Palestinian terror attacks on Rome and Vienna airports last week. Who killed them?

Yasser Arafat undoubtedly did not order these attacks. Abu Nidal, leader of a breakaway faction of the PLO, almost certainly did. Arafat has deplored the whole affair, and some, like the Austrian government, made absolving him their first post-massacre order of business.

It won't wash. It is time, after two decades of Palestinian terror, for Palestinian leaders to take responsibility -- "credit" they used to call it in the days when they openly embraced terror -- for the monsters they have created.

In its 20 years, the PLO fashioned a cult of righteous violence, an ideology of terror. Terror was not only justified as a military necessity but glorified as a reclamation of Arab dignity. Attacks on civilians were accorded the language of war. Victims were called "targets," killers "commandos," murder "an operation." All was reported in a "communiqu,e." Indeed, Arafat's greatest achievement -- to the sorrow of his suffering people, his only achievement -- is to have made terror respectable. He brought it to Western capitals, where it earned acquiescence, to the podium of the U.N., where it drew applause, and to young Palestinians, where it shaped the imagination of a generation.

Now, it seems, Arafat has had enough. He now declares, before the right audience, that he wants to turn the terror off. But he can't. Barbarism springs up again in Rome and Vienna, and Arafat now piously deplores it.

But after all, who are these new young killers if not his disciples, determined to follow his original gospel, not his late revisionism? From whom, after all, did the PLO "splinter groups" learn to hijack and murder? Where does Abu Nidal, once the PLO's man in Baghdad, now carrier of the tradition that Arafat has wearied of, come from -- if not from the cult of terror that Arafat developed over two decades?

At every level, Arafat's new found renunciation of terror rings hollow. First of all, in large part, the renunciation is a lie. The PLO denied involvement in the Achille Lauro affair and the murder of three middle-aged Israelis on a yacht in Larnaca, Cyprus. Like the "Black September" Munich Olympics massacre (also reputedly and conveniently carried out by a PLO "offshoot"), these attacks were, in fact, directed by Arafat's PLO.

Moreover, Arafat makes clear that his non- terrorism stance, such as it is, is just a tactic. Terror has now become a diplomatic inconvenience. But there is no repudiation of terror in principle. No condemnation of past terrorist acts. No theory to explain why the murder of innocents is wrong, rather than just bad public relations.

How can there be? Arafat's post-Achille Lauro "Cairo declaration" opposes terrorist attacks -- except if they take place in Israel. The wrongness of terror is purely a matter of geography, not morality. If so, if forswearing terror is a matter of tactics, not principle, then it is inevitable that other Palestinians will come to different tactical conclusions. They evidently did in Rome and Vienna.

The sanctity of life is not a major PLO theme. Farouk Kaddoumi, Arafat's "foreign minister," spoke last month at a U.N. lunch attended by the U.N. secretary general. He said this of Leon Klinghoffer: "Perhaps it might be his wife (who) pushed him over into the sea to have the insurance. Nobody even had the evidence that he was killed." What are the murderers of Vienna and Rome responding to if not a lifetime of such lessons in cynicism?

Lessons thoroughly learned all over the Arab world. Last October an Egyptian policeman opened fire on Israelis vacationing in the Sinai. He murdered seven, including four children. An Egyptian cour sentenced him to life imprisonment. The Egyptian opposition held large demonstrations calling for the release of the "hero of Suez." The National Assembly of Kuwait -- "moderate" Kuwait -- demanded that he be not just freed but honored for having "restored to the Arab people some of its dignity."

To call the murders at Rome and Vienna senseless is mere intellectual laziness. They were not. In a political culture where the existence of Israel is in itself an act of aggression, and the murder of Israeli children is a restoration of national dignity, what happened at Rome and Vienna is perfectly logical. When one of the surviving Vienna terrorists was asked why he attacked so many innocent people, he had his answer: "Because it is Israel. We kill Israel." QED.

Only a few years ago Arafat took "credit" for such acts. Even now, so long as they take place in Israel, he still takes credit. Today, however, regarding murder in Rome and Vienna, he plays the innocent. He is too modest. He deserves the credit here, too. That the godfather of modern terrorism may now equivocate on the subject is a diplomatic nicety. It is also a historical irrelevancy. His work is done. His children carry on.