Israel's campaign to destroy or expel armed Palestinians from Lebanon is remarkable for its duration, tenacity and ferocity.
Why has the government of Israel pressed this type of campaign against the Palestinians even at the price of death and destruction among half a million innocent Lebanese in West Beirut, offense to humanitarian sensitivities the world around and erosion of support for Israel in the American Congress (without which Israel cannot survive)?
The explanation is to be found in the terms of the Camp David peace process. The next item on its agenda is the establishment of an ''elected self-governing authority in the West Bank and Gaza'' which is supposed to lead almost at once to withdrawal of Israeli armed forces from most of the West Bank and Gaza ''into specific security locations.'' The police authority in the West Bank and Gaza would pass into the hands of a ''strong local police force'' to be constituted by the self-governing Arab authority.
In other words, if Israel is to honor the provisions of Camp David it should begin right now a process which was intended and expected by the Americans and Egyptians at Camp David to lead to a sharing of the ancient Land of Canaan between the Arabs and Jews.
The immediate battlefield has been along the road from northern Israel to West Beirut. The real issue which is influenced by this battle is whether Palestine is to be shared or become in its entirety the property of Israel as Israeli Prime Minister Menachem Begin obviously, and avowedly, intends.
The Camp David process is already behind schedule. The first item on its agenda was to be a peace between Egypt and Israel. That was supposed to be signed three months after the conclusion of the Camp David process. It stretched out to six months. Talks for Palestinian self-rule should have started one month after exchanges of ratificiations of the peace treaty. They have yet to begin seriously.
The setting up of an Arab autonomous authority for the West Bank and Gaza should have happened long ago. It was put off largely because everyone agreed that the establishment of a peace between Egypt and Israel was itself a complicated and delicate matter. Getting Israeli troops back out of Sinai was considered to be about all the traffic American diplomacy could handle at one time. That process was completed in March. That was four months ago. Since then Mr. Begin has tightened further his grip on the West Bank and Gaza, driven the armed forces of the Palestinians farther away from Palestine and pushed them into a position in which he threatens to kill them outright unless they go away beyond military reach of their own homeland.
The more the delay in getting on with the Camp David process the tighter is Israel's control over the West Bank and Gaza and the weaker the Palestinians and their case seem to become. People tend to forget that in 1978 Mr. Begin signed documents which the American and Egyptian Presidents at Camp David thought would give the Arabs their own homeland, under their own elected Arab leaders and under their own Arab police forces, inside Palestine.
At the time of Camp David the Arabs did have mayors of their own choosing in their own cities. But beginning last year Mr. Begin began dismissing those elected mayors and trying to set up in their places local groups handpicked by Israelis among Arab collaborators. These collaborators who take Israeli orders are regarded in the Arab community as renegades or traitors. People who remember World War II would call them quislings. They do not fulfill the provisions of Camp David for Arab leaders to be elected by the Arabs.
What we are really watching in all the maneuvering and the fighting is a struggle over whether the land of Canaan is to be shared between Arabs and Jews as intended at Camp David or become in its entirety the possession of the Jews.
This is the second time this issue has been fought out. When the tribes of Israel first invaded the land of Canaan in Biblical times (about 1225 B. C.) they conquered all they could, but could not take it all. For example, they captured Hebron and Gaza but were unable to take Jerusalem.
As the Book of Judges, first chapter, tells the story, ''the Canaanites would dwell in that land.'' So the Israelites ''put the Canaanites to tribute, and did not utterly drive them out.''
One can only wonder how far this second invasion of the Land of Canaan will resemble the story of the first invasion as told in the Book of Judges. If the intent of Camp David prevails, the land will be shared between Jews and Arabs, both living under their respective laws, police, and judges. If Mr. Begin prevails, the Canaanites will once more be ''put to tribute'' and he, not they, will decide which of the refugee Palestinians may return to their native homeland.