CONGRATULATIONS ON your election victory, Mr. Prime Minister-to-be of Israel -- whoever you are. It will take you and your fellow politicians some time to sort that out, we gather. No matter. There is on the newly chosen leader one obligation surmounting all others: to return to Camp David.

Recall that Camp David had two "frameworks." No. 1 was a "framework for Peace in the Middle East," calling for "negotiations on the resolution of the Palestinian problem" and for peace between Egypt and Israel." On the Israeli side, both were signed "For the Government of Israel: M. Begin" on Sept. 17, 1978.

From that day, the government of Israel -- meaning Mr. Begin -- has dealt in good faith with Egypt and in dubious faith with the Palestininas. It is not simply that Mr. Begin, to his regret, found Palestinians unresponsive to the lures of Camp David. He has acted to ensure they would be unresponsive by promoting West Bank settlement in a manner contemptuous of the spirit of the agreement and by offering as version of Palestinian autonomy seemingly calculated to repel all self-respecting Palestinians. He has made ever more explicit his religious and party commitment to holding on to the West Bank forever. Indicatively, he has tried, according to Abba Eban, to popularize a Hebrew "translation" of the Camp David text in which "Palestinians" and "Palestinian people" do not appear at all.

He has done all this despite his Camp David pledge to let the "final status" of the West Bank and "the location of the boundaries" be determined by negotiations in which elected Palestinians would take part and would then vote on; and to see that "the solution from the negotiations must also recognize the legitimate rights of the Palestinian people and their just requirements." These are not the words of the PLO or the Labor Party or an American president or a European diplomat. They are the words of a solemn agreement signed "For the Government of Israel: M. Begin."

The American government, and others, have a bit of time to analyze the emerging political configuration in Israel. Any serious policy devoted to moving toward peace in the Middle East, however, must go back to Camp David. Labor's Shimon Peres reads its Palestinian part differently from Mr. Begin. Mr. Reagan had detected "basic ambiguities" in it in the past. But Camp David remains the single, relevant, existing contractual basis on which the United States can act. To release Mr. Begin in particular from his -- from Israel's -- Camp David vows would be recklessly foolish. Surely he is as good as his word.