A NEW WAR in the Middle East would be tragic for everyone involved, not only in terms of loss of lives, but in that it would probably put a permanent settlement far out of reach for many years to come.

All parties should realize that there is no military solution to the Middle East problem. And all sides should be prepared to make serious concessions and fundamental changes in their positions in order to achieve a reconciliation and end further senseless bloodshed.

Clearly there are two primary and essential steps that must be taken toward negotiations between Israel and the Arab states, and between Israel and the Palestinians. All Arab governments and the Palestine Liberation Organization should declare their willingness to recognize Isreal's right to exist as a sovereign state.

And Israel should acknowledge that there is a Palestinian national entity, that Palestinians have a right to a self-governed state, and that Israel is prepared to enter into negotiations with the P.L.O. to achieve that end.

No real progress can be made unless both sides come to terms with these realities. This means that the P.L.O. will have to abandon its stated goal of a "democratic-secular state between the Jordan and the Sinai"--which is simply a codeword for the destruction of Israel and its replacement with another Arab state. Israel will have to abandon its claim that Palestinians already have a homeland in the Hashemite Kingdom of Jordan. And Arab governments should support negotiations between Israel and the Palestinians in which both sides recognize each other's right to exist. Each party should pledge not to engage in any actions against the other during these negotiations.

It is particularly important for Israel to state that it is prepared to sit down, not with just any Palestinians, but with the P.L.O. It is apparent that the P.L.O. has as much claim as any group to be the representatives of the Palestinians on the West Bank, in Lebanon, and in Syria--particularly after last week's pro-P.L.O. demonstrations on the West Bank. Although a plebiscite among all Palestinians to determine who should represent them in negotiations would be preferable to simply naming the P.L.O. such a plebiscite unfortunately appears to be impossible.

The record of P.L.O. crimes against innocent civilians in Israel and around the world is deplorable and must be condemned, but any negotiations which seek a real and lasting solution must include the organization.

The viability of a West Bank Palestinian state is clearly questionable, but with the support of all parties it might represent something of a solution. Certainly such a state should not be ruled out.

The historic roots of the Middle East conflict are deep, and decades of wrongs on all sides have created the existing impasse. With two territorial claims to one plot of land, the only realistic solution is to partition the land. Though partition failed once, perhaps repartition will have a greater chance of success with both Arabs and Israelis recognizing each others' needs, aspirations, and rights. It is not an ideal solution, but given the history and the current situation, it seems the only practical one.