ALL THE SIGNS surrounding Menachem Begin's visit to Washington indicate that, to be precise, the Carter administration has give up on the hope that he can make the changes of Israeli policy necessary to sustain a negotiation with Egypt's Anwar Sadat and to open a negotiation with the other Arabs whose partnership is required for peace. The administration seems now to have concluded that Mr. Begin's refusal on religious grounds to regard withdrawal from the West Bank as negotiable, and to treat the West Bank in the more manageable terms of a security issue, represents deeply held views from which he will not budge. In the administration's view, Mr. Sadat cannot and should not be asked to make a separate arrangement with Israel without first obtaining agreement on the principles that would govern further negotiation and ultimate resolution of West Bank issues vital to other Arabs. It is because Mr. Begin will not offer that assurance that President Carter apparently feels the peace process is at an impasse.

Israell officials, citing the administration's warm response to Mr. Begin's Sinai plan in December, read this as plain evidence that American policy has changed. It is an inaccurate reading. The administration was indeed impressed by the Sinai plan, without considering it the last word. Since, however, it has come to believe that Mr. Begin, for all of his professions of willingness to negotiate on any question, is not going to accept any arrangement requiring Israeli withdrawal from the West Bank. In that territory, in other words, the terms of U.N. Resolution 242 do not apply, and Arab sovereignty is not going to be restored - by any agreement with an Israeli government under Mr. Begin's control.

The Israeli prime minister has also proven himself unwilling to consider the alternatives the United States suggests to reduce any security threat to Israel emanating from the West Bank: limited withdrawal, Israeli contonments, restrictions on the independence and capabilities of a new Palestinian entity, American and other guarantees, and so on. American policy has not changed. American policymakers have simply come reluctantly to a realization that Mr. Begin's bargaining position is not an opening bid but a matter of religious belief.

The administration understands the implications of coming to the judgment, and of letting it be known, that it has reached the end of the line with Mr. Begin. This halts whatever prospect of negotiation around the edges, let alone at the center, there might have been. It creates the possibility of a momentous American-Israeli showdown. Some American friends of Israel will surely call for a political mobilization in order to beat Mr. Carter down and to spare Israel the agonizing reappraisal that otherwise the administration's decision means for it. It is a mark of Jimmy Carter's seriousness, we note, that he is ready to accept the political as well as the diplomatic risks - in an election year.

We hope, nonetheless, that Israeli will not flinch from the indicated reappraisal. Perhaps it is in Mr. Begin to take Israel out of the painful situation he has led it into. That is for th Israelis to decide. Israeli political society was already virtually bursting with questions and doubts about his leadership. The sense of confrontation will doubtless throw some Israeli critics back into Mr. Begin's corner. But others, we believe, will respond to the imperatives of Isreal's situation. Chief among those is the need not to lose Anwar Sadat as a negotiating partner. No one better from the Israeli viewpoint is in officer or in view.

If the United States, by joining the issue, is forcing an excruciating internal crisis upon Israel, then Israel has the right to make certain demands on the United States. It can insist that Washington scrupulously avoid further detailed intervention in Israeli politics, say, by picking - and thereby probably disabling - a particular successor. It can expect that the United States bend all its influence to seeing that Arabs do not try to exploit Israel's distress. It can demand that the United States take no interim steps to alter the existing military balance, or to make Israel fear the balance is beign altered. it can expect the administration to become progressively more specific and definite about the security arrangements it poses as alternatives to Israeli tenure in the West Bank.

This will be a tortuous time for Israel and the United States. We hope we do not underestimate the difficulties in saying that one way or another they can, and must, be met.