Begin's great offensive

It is now possible to see the full scope of the offensive operation which Israeli Prime Minister Menachem Begin launched on June 6 of last year. His troops now occupy all of southern Lebanon up to the airport just south of Beirut. His diplomats have been negotiating with the Lebanese since Dec. 28. The two weeks of talks to date have dealt exclusively with the agenda. Israel is demanding that Lebanon accept ''normalization'' of future relations between Lebanon and Israel as the priority item before taking up Israeli troop withdrawals.

''Normalization'' is defined as meaning an Israeli government office in Beirut and unimpeded trade and tourist traffic over their common frontier.

In addition Israel is asking as a further preliminary to withdrawal of Israeli troops that Lebanon agree to a 25-mile ''deep security zone'' in southern Lebanon. In this zone there would be three Israeli observer stations. Israeli military aircraft would have the right to fly reconnaissance over the zone. The Lebanese army would not be allowed to bring heavy weapons into the area.

In other words, Israel expects to retain effective control over the southernmost 25 miles of Lebanon, enjoy full commercial and tourist access to Lebanese markets, and be recognized diplomatically by the Lebanese government.

The invasion was launched in spite of urgent pleas from the United States. It was condemned as an act of aggression by the United Nations. No government other than that of Israel itself accepts the theory that the invasion was provoked by the PLO. Indeed it followed an 11-month truce broken repeatedly by the Israelis but hardly at all by the PLO.

Throughout the weeks of the invasion itself and ever since the Israeli government has proceeded to build more housing for Israeli settlers in the occupied territories of the West Bank, Gaza, East Jerusalem and the Golan Heights. The present number of Israeli settlers in occupied territory is now estimated at 25,000. These are in 110 settlements of varying size. More settlements are being opened and building is going on at a rate estimated to provide housing for another 75,000 persons during the next two years.

To achieve this goal there would have to be enough new housing completed every week on average for 722 persons. Construction is estimated to be at a rate sufficient to take care of new settlers at that rate. Housing in the new settlements is offered at subsidized rentals. A sample family can reduce its monthly rent from $200 to $60 by moving from Israel into one of the new settlements.

President Reagan on Sept. 1 launched what he hoped would be a new diplomatic drive for a comprehensive peace between Israel and its Arab neighbors. He proposed that Israel cease all building of new settlements for Israelis in the Arab territories. Had Israel accepted that proposal by the President of the United States, the kingdom of Jordan was ready to join in the peace talks aimed at revival of the Camp David process.

But so long as the building of the new housing goes on, King Hussein, and other Arabs, are effectively prevented from joining in the peace process. If they did join, they would be condoning and, by implication, giving their approval to the annexation by Israel of the occupied territories.

There was hope in Washington at the time of the President's peace proposal of Sept. 1 that Israel would be satisfied by its victory over the PLO in southern Lebanon and be ready to proceed down the peace road under the Camp David formula.

But both Camp David and President Reagan's plan of Sept. 1 call for the withdrawal of Israel from most of the occupied territories as contemplated by UN resolution 242 - which Israel helped to write and accepted in 1967. In return the Arab countries would recognize Israel.

Prime Minister Begin has not halted the building of the settlements. He has ignored the President's wishes. The Congress has nevertheless voted the usual American subsidy to Israel for 1983, and in fact has increased it in spite of a request by the President to not do so. In other words, American taxpayers are subsidizing the expansion of Israel both into southern Lebanon and into the new settlements in the occupied territories in defiance of the wishes of the American President.

Peace is imposible so long as the annexation process continues. The building of the settlements can be stopped only by the President and only if the President is willing and able to join the issue in Congress over the American subsidy to Israel. If he could stop the subsidy, Mr. Begin would be forced to call off the building of new housing for settlers and also be forced to withdraw his troops from Lebanon.

This could be done only at the price of a bruising political battle in Congress between the President and the pro-Israeli lobby. There is no certainty that the President would win. If he did accept the issue and win, then his peace plan could move ahead. If he does not, Israel will end up in effective control of southern Lebanon and of all the occupied territories.

That would be the road to the next Arab-Israeli war.