Come with me on a tour of Lebanon. We are in the back seat of a car with an Israeli army escort whose English, by virtue of years spent in America, is downright colloquial. Down by his left leg he keeps his Uzi submachine gun, and to his right is a briefcase full of maps and data. Together, the rifle and the data explain why Israel is in the mess it's in today -- why it must share the blame for the massacre of Palestinians in Beirut.

With the rifle, Israel has been able to take all of Lebanon up to and including the city of Beirut. Its army is an awesome fighting machine, by far the most powerful in the Middle East, and its organization is impressive. Within days after the invasion, it had virtually taken over the civil administration of cities and towns, was familiar with mayors, headmen, doctors, lawyers -- everyone who mattered.

Equally impressive is the data in the briefcase. For every question, the Israeli major has a document with the answer. He can tell you the number of Druze in the region, the number of Moslems and whether they are Shiite or Sunni. He knows the history of the sects, the significance of the local shrines. He can speak with just as much authority about the Christians -- the Maronites, the Greek Orthodox, the divisions within the divisions. The list, it seems, is endless, but so is his data.

This is what it was like in Vietnam. Oh, the terrain is different, of course -- and the people and the situation, too. But what is the same is the hubris of thinking that a combination of military might and intelligence data can somehow bring order to chaos -- that with tanks and computers you can impose a military solution on a political problem. This was the mistake of Vietnam and this is the mistake of Israel's disgraceful adventure in Lebanon.

It is difficult to believe that Israelis, given their national character, would either participate in or sanction a massacre. It is not that kind of country and it is not that kind of army. But, if it is proved otherwise, Israel has lost something precious -- its moral standing. At any rate, as they say in the U.S. Navy, the massacre occurred on their watch. It occurred in a city that the army had seized ostensibly to prevent that sort of thing from happening, and it happened after similar things had happened time and time before. There was ample reason to believe that the PLO knew what it was talking about when it expressed fears that with its fighters removed from Beirut, some element of the Christian community would do what it in fact did.

Lebanon is that kind of place. Feuds go back to medieval times. It is a country of Hatfields and McCoys, only the Kentucky long gun has been replaced by the Kalashnikov automatic rifle. Religion is pitted against religion, sect against sect, family against family. The place festers with private armies and appearances are deceiving. Underneath Paris-made shirts and Gucci shoes, the fluent French and the charming urbanity, lurks the mentality of the crusader. In Lebanon, clothes do not make the man; they conceal him.

Back in our car, though, the major would concede none of that. He had his facts and figures. The intelligence work had been done -- and done well. And back at army headquarters in Tel Aviv there was a wall-sized aerial photo of Beirut. On it, you could see every house, even cars and people on the street. The situation, an intelligence colonel said, was manageable.

Vietnam had the same aerial photos and the same wonderful intelligence work, not to mention the best army in the world. But knowing is not the same as controlling and there was a limit, even for the United States, to the number of troops it could commit for a war that for Americans had almost nothing to do with national security and everything to do with political aspirations.

It is the same for Israel in Lebanon. It has stepped into its own quagmire, taking, as we did in Vietnam, the killers of women and babies as allies, overestimating what it could do, underestimating the extent of the problem. Arrogance has caused Israel's reach to exceed its grasp.

What that major needed in the car that day -- and indeed what all Israel needs -- is neither a better gun nor more facts, but a lesson, if not in humility, then in history. It ought to do what we finally did when faced with an unnecessary war that corroded our spirit and soiled our national honor: Bury the dead and get out.