THE PRESIDENT'S Mideast warplane proposal comes to a first and possibly conclusive vote, in the Senate Foreign Relations Committee, today. To our previous support for the proposal, we add a few comments based on the debate in recent days.

We would begin by stating the obvious: The world would be a safer place if everybody were at peace and nobody were selling arms to anybody. But the Middle East is in a state of restrained hostilities that prompts all of the parties to the conflict to want more armaments.

Somebody is going to meet that demand - if not the United States. Thus it seems to us to make sense, at a stage when this country is trying to promote accommodations and concessions from Arabs and Israelis, to honor reasonable arms commitments made to both sides rather than to furnish sophisticated weapons exclusively to Israel.

The administration has been responsive to anxieties expressed by Israel's backers. The Israelis have been promised an additional 20F15s, and Congress has won written assurances that the F15s bound for Saudi Arabia will be limited in basing and armaments and will not be supplemented by equipment or planes obtained elsewhere - say, France. Yes, those are concessions the administration had ready in its pocket, and the administration had ready in its pocket, and the administration owed no less to Israel to make up for the decision, made after the promise to sell planes to Israel, to sell planes to Egypt and Saudi Arabia, too. But they also involve very substantial concessions by Saudi Arabia. No one argues that Israel's security is enchanced by the sale to the Saudis, but surely it is worth something that the Saudis accepted the conditions that Congress demanded of the administration.

Many in Congress wish the plane deal were deferred until progress comes in Arab-Israeli peace talks. We felt that way until it became clear that none of the three intended recipients wishes to have this key aspect of its defense planning, and of its overall association with the United Sates, left in limbo. The plane deal can strengthen, we believe, the relationship Washington needs with each of the three to secure its reasonable part in the peace effort.

Much - too much - has been made of the airplane debate as a confrontation between the Carter administration and the "Israeli lobby." That is understandable, given that the Saudis and Egyptians would be breaking Israel's 30-year lock on major American arms acquisitions in the Middle East. In fact, our impression is that the pro-Israel lobby has been no more active, and probably rather less effective, than the Arab or Saudi lobby. Thanks to them both, the president's proposal has received thorough scrutiny. It has been modified in important aspects. A decision on it will reflect an informed national consensus. As we read it, that consensus holds that the United States has good reason to maintain close ties with Arabs as well as Israelis - the better to facilitate their progress toward peace.