THE CHAOTIC scenes of Jewish settlers in the Gaza Strip scuffling with Israeli soldiers -- jeering and spitting at them, calling them Nazis, pelting them with eggs and blocking their approach with burning piles of trash and tires -- must be agonizing for Prime Minister Ariel Sharon and the Israeli army. After all, Mr. Sharon, whom some hysterical settlers liken to Hitler for his decision to evict them from Gaza, is the same leader whose strategic and ideological vision once made him the settlers' champion and the political godfather of their movement to implant Jewish communities on land captured from the Arabs in 1967. And the Israeli army is the same force whose dangerous, costly presence in Gaza has protected these settlers and guaranteed their livelihoods for decades.

Under those trying circumstances, both Mr. Sharon and the army have acted thus far with exemplary conviction and restraint in carrying out the eviction. Despite several thousand settlers who are refusing to leave their Gaza homes voluntarily, and a few thousand more Israelis who have entered Gaza to help them defy the troops, the evacuation is proceeding deliberately and professionally. Mr. Sharon, for his part, has struck a resolute tone that has left no doubt about either the difficulty of his decision or his determination in carrying it out.

"It is no secret that, like many others, I had believed and hoped we could forever hold on to Netzarim and Kfar Darom," two of the Gaza settlements being evacuated, he said in an address to the nation. "But the changing reality in the country, in the region and the world, required of me a reassessment and change of positions. We cannot hold on to Gaza forever."

What Mr. Sharon calls his "unilateral disengagement plan" will advance the chances of peace only if Palestinian Authority President Mahmoud Abbas reciprocates by disarming and bringing to heel groups such as Hamas, which are responsible for many terrorist attacks on Israel. And it will bear fruit only if the Israeli leader stands ready for further negotiations toward the eventual establishment of a Palestinian state. Mr. Sharon and his advisers have given mixed signals on that theme, and on the prospect of further territorial concessions in return for Palestinian steps toward peace. By telling Israelis the other day that the withdrawal from Gaza "will allow us to look inward" at domestic social and economic problems, he did little to reassure Palestinians and the world that he intends to pursue a durable solution to the Mideast's most intractable conflict.

In the coming days Mr. Sharon's hand will need to remain steady, for the situation in Gaza could easily deteriorate. Already this week, an Israeli woman lit herself on fire at a crossroads near Gaza, injuring herself severely, evidently to protest the evacuation. In the West Bank, a Jewish settler snatched a gun from an Israeli security guard and shot three Palestinian workers to death, the second such incident in less than two weeks; Palestinian militant groups threatened retaliation. In Gaza itself, hard-line Israeli religious nationalists, many of them interlopers from West Bank settlements and some in the grip of messianic zeal, believe they can force the government to reverse its evacuation order by causing scenes of sufficient mayhem.

Mr. Sharon is clearly equal to the immediate challenge of withdrawing from Gaza. The question is whether he is up to the long-range one of securing a lasting peace.