April 25 is a milestone in the history of the Middle East. Unlike so many others in the area, it is a constructive one.
Israel's return of the last segment of occupied Sinai to Egypt is, in effect, the consummation of the declared intent of those two countries to live in peace with each other.
This comes nearly 34 years after the establishment of the state of Israel and after four Arab-Israeli wars: 1948-49, 1956, 1967, and 1973.
The significance of the date can all too easily be lost in the haggling that has attended the final phase of the Israeli withdrawal. For a moment the crash of Israeli bombs on Palestinian outposts in Lebanon may drown it. But it is significant. Peace has come to Israel's frontier with its most important and powerful neighbor.
If this peace is a monument to the vision of any single man, that man is the late Anwar Sadat. It was first the war of 1973, paradoxically launched by him to secure peace, and then his dramatic visit to Jerusalem in 1977, that broke a mold of armed conflict and rhetoric into which Arab-Israeli relations had been locked for three decades.
Others contributed once the mold had been broken - former Secretary of State Henry Kissinger, former President Carter, and even Israel's hard-line Prime Minister Menachem Begin.
But as Dr. Kissinger writes in his latest volume of memoirs: ''None who knows history will ever forget that the journey to peace in the Middle East began with Anwar Sadat, and could not have progressed without him. Whether we reach our destination is up to us. For his part, Anwar Sadat has already earned the immortality of which his ancestors dreamed - as an inspiration if we succeed, as a shaming example if we fail. One way or another, the cause of peace will be his pyramid.''
There are still those in the Middle East who revile Sadat for what he did - not least the Palestinians, who, humiliated and dispossessed, have paid a higher price than anybody else for the establishment of the state of Israel. If a broader, lasting peace is to come to the area, their grievances must be given a hearing and at least partially met.
Admittedly it has been easier for Israel to withdraw from sparsely populated Sinai than it will be to persuade it to give up any part of the occupied West Bank and Gaza. But the importance of Sadat's initiative is that it proved the feasibility of implementing those UN Security Council resolutions that were based on the principle of offering Israel peace with its neighbors in return for Israeli withdrawal from land seized in the 1967 war.
In retrospect, the establishment of the state of Israel after World War II was one of those movements of peoples that have occurred throughout history -- exhilarating to those effecting it, but brutal and unjust to those displaced by it.
The war of 1948-49 was an effort by threatened and displaced Arabs to prevent Israel's emergence as a state. They failed, but refused to recognize or accept what had happened. The war of 1956 was, in part, a resort to arms by the Israelis to force the Arabs to come to terms. The result was an Israeli military victory but a diplomatic standoff.
The 1967 war, ending in the most decisive and crushing of the three Israeli military victories, can be seen as having established once and for all that Arab hopes of removing Israel from the map as a political entity were unrealistic. But the humiliation inflicted on the Arabs made them more determined than ever not to come to terms with Israel or accept any Israeli diktat.
The 1973 war, launched by Anwar Sadat, brought initial Arab successes and the psychologically all-important crossing by the Egyptians of the Suez Canal. Despite Israel's recovery and turning of the tables before hostilities ended, Sadat had achieved his twin purposes: the recovery of Arab self-esteem and active cooperation of the US in the search for peace.
On the Israeli side, there had been a parallel psychological change opening the door for a fairer compromise peace than had ever been possible before.
The initial Arab victories in October of 1973 shook Israeli convictions that peace could be imposed on Israel's terms. Secretary Kissinger's maneuvers then produced a stalemate on the battlefield, which was a prerequisite for negotiation. And in the UN, Israel accepted for the first time the principle of withdrawal from occupied territory in return for peace.
Dr. Kissinger's shuttle diplomacy followed. When that had run its course, Anwar Sadat broke the deadlock with his journey to Jerusalem. When that initiative stalled, President Carter revived it by coaxing Mr. Begin to cooperate on the Camp David accords.
They have led to this April 25 milestone. There is now peace between Israel and Egypt. The toughest part is probably still ahead - involving Israel's other neighbors (Syria, Jordan, and Lebanon) and the Palestinians. Some may doubt Mr. Begin's willingness to repeat the process begun in Sinai on Israel's other borders. But this in no way lessens the importance of April 25 as a milestone and an example.