President Reagan has adopted a statesmanlike position in committing the United States to working for a Middle East peace settlement in the wake of the events in Lebanon. His ringing speech this week is but the first step after a long period of drift in US policy. It is a remarkable first step, however. By stating so forcefully the prerequisites for a permanent peace - security for Israel and self-government for the Palestinians - and offering an approach to a final settlement, Mr. Reagan gives promise that the United States will now be actively engaged in the quest for peace.
That is crucial, for progress cannot be made in the Middle East without a strong American role. If the President follows through on his own ''fresh start'' with firmness, courage, and vision, it is just possible the long-elusive goal of resolving the conflict between Jews and Arabs will be achieved.
There is no escaping the difficult problems ahead. But, most important, the President has reaffirmed the fundamental framework for peace: implementation of UN Resolution 242 calling for Israeli withdrawal from occupied territory and of the Camp David accords providing for self-government for the Palestinian people. He thus aligns himself with the policies of his predecessors, suggesting that he has learned the hard realities of the Mideast and is prepared to support the bipartisan approaches of past US administrations. Even his proposal for a final outcome - an ''association '' of the West Bank with Jordan after a five-year interim period - is in line with the views of President Carter, who also opposed establishment of an independent Palestinian state.
An early need will be to draw the Arabs into the West Bank autonomy negotiations. In this connection it is not clear that it was wise of the President to put forth a specific solution, however vague a one. It seemed somewhat inconsistent to say that everything has to be ''negotiated'' and then rule out in advance the option of a Palestinian state (or, for that matter - hard as it is to imagine now - a Palestinian association with Israel). In any case, it is to be hoped that the Arabs will not be tempted, because of the President's own formula, to resist negotiations, but will see in his forthright speech an opportunity to forward the peace process, to work closely with the United States, and to build up the support of American public opinion. Too often in the past, the Arabs have reacted negatively to events and in the end lost a chance for progress.
Israel, for its part, already has turned down Mr. Reagan - a negative reaction that tends only to confirm doubts about its true intentions in the West Bank. In recent years Israel has steadily tightened its grip on the area. Jews now own or control substantial portions of land in the West Bank, and it is no secret that hard-line Israeli leaders, including Menachem Begin, consider the West Bank a part of the land of Israel (they now call the Palestinians there the ''Arabs of the land of Israel''). Even the invasion of Lebanon and defeat of the PLO are seen to be a prelude to accelerated Jewish settlement of the West Bank and ultimate annexation of it.
Israel's summary rejection of the Reagan plan, including his call for a freeze on settlements, should not be regarded as the final word, however. One would expect a tough opening bid from the Israelis under any circumstances. This is why it is especially important for Jordan and other Arab states to respond positively and lend momentum to Mr. Reagan's initiative. By doing so, they can help strengthen the voice of those moderate Israelis, including members of the Labor Party, who are sympathetic to a negotiated accommodation as well as bolster bipartisan US public opinion. They would thus be building a moderate consensus and laying a bridge to peace.
Mr. Reagan, in short, is finally on the offensive. The President is forcing the pace of diplomacy and reaffirming the ground rules for it. But his speech is not a full-blown policy; it raises questions and contains flaws. The challenge ahead will be to engage the reluctant Arabs, to stand up to a headstrong Israel, and to stay involved in the daily, arduous, painstaking work of hammering out positions and negotiating.
Peace and justice - for Jews and Palestinians - demand that Mr. Reagan rise to it.