Begin's bitter -- but finest -- hour

What may be Menachem Begin's finest hour is the confrontation he is forcing, against all his old instincts, with nationalist diehards in Sinai in the name of an uncertain peace.

Seared by the holocaust he narrowly escaped and himself at the focus of a battle of brothers during Israel's war of independence, Begin has manifested a near traumatic aversion to pitting Jew against Jew. Abrasive as he may often be in his dealings with the outside world -- and indeed with his own parliamentary opposition -- Begin is deeply sentimental about the well-being of fellow Jews.

The Israeli militants in the Yamit region of northeast Sinai had been counting on that sentimentality in their plans to foil Israel's scheduled pullout from Sinai April 25. They hoped to bring down tens of thousands of supporters in the final weeks, leaving Begin with the choice between bloody evacuation or surrender.

''There is no army in the world that is capable of removing ten thousand people without shedding blood,'' Begin told the Knesset recently. ''There is no choice but to use live ammunition. I made an irreversible decision not to shed Jewish blood in connection with the peace treaty. I will resign but I will not shed blood.''

However, Begin also had made an irreversible decision to honor Israel's pledge to leave Sinai. At Camp David, he had made his leap into the psycho-political void, adjusting his life-long commitment to a greater Israel as homeland for the Jewish people in the hope that the glimmer of true peace offered by Egyptian President Anwar Sadat heralded a new era in which Israel could finally lower its sword.

Shortly after taking office in 1977, Begin had announced that he would eventually retire to a Sinai settlement on the Mediterranean coast, and a house was set aside there for him. He saw in the pioneering young settlers creating a green oasis in the desert beyond Israel's former border the epitome of his own faith in a vibrant Jewish state propelled by a sense of mission.

Two years later, after the soul searching and pressure-cooker diplomacy of Camp David, he signed away that house, the settlement, a score of others, and all of Sinai.

Israel has meticulously honored its staged withdrawal from Sinai during the past three years. Its hour of trial, however, is now at hand with the imminent pullout from the last corner of the peninsula. The militants planning to thwart Begin are his former devotees, old believers who refuse to be tempted by the siren call of peace.

They had hoped that Begin's commitment to the peace process would be weakened by Egyptian intransigence. They drew heart from the tough Egyptian line in the Palestinian autonomy talks, Cairo's refusal to make concessions in drawing the border line in Sinai, and the refusal by Egyptian President Hosni Mubarak to visit Jerusalem. Begin, however, has declined to seize on any of these as an excuse for reneging on Sinai.

When the time for action in Sinai came recently, on the eve of a planned large-scale incursion by militants, Israeli Defense Minister Sharon moved swiftly and massively. Deploying several regiments he caught the militants off guard and was able to begin the evacuation with relatively little opposition.

The militants, who have proven their organizational ability and determination in the past, will undoubtedly attempt to make the pullout as painful as possible in the coming weeks. Aside from the loss of Sinai itself, they are fearful that its evacuation can set a precedent for the settlements on the West Bank in the event of some future peace settlement with Jordan or the Palestinians. There is little chance, however, of the militants outmaneuvering or outtoughing Sharon, himself a superhawk.

It is with Begin that the ultimate responsibily for the Sinai evacuation rests and he has made his determination clear. ''Let it be known,'' he told the Knesset recently, ''nothing will avail. No shout, no attempt to muster masses. This is a bitter hour for us all. It is woeful that I have come to this. But I have come to this, and I will carry out my obligation to the end.''