he Palestinians have often been called the Jews of the Arab world: a stateless people dispersed in a diaspora, living by their wits, pining for a return to their historic homeland. This is not a comparison either side likes. It implies an equivalency that both reject.

Yet the comparison remains common, even among Israelis and Palestinians themselves. Palestinians study the milestones of the Zionist movement for guidance and often speak about the Israeli political system, with its freewheeling debate, as a model for their own.

There is one milestone in particular that bears study today — David Ben-Gurion's fateful decision in 1948 to end Jewish terrorist activities and bring armed splinter groups under government control. When Ariel Sharon and Mahmoud Abbas, the Israeli and Palestinian prime ministers, met last night and prepared to see President Bush next week, one of the biggest issues they discussed was ending the terrorism of renegade Palestinian groups. Mr. Abbas said that by next week he hoped to have a pact with Hamas, the main Palestinian Islamic party, to halt violence against Israelis.

Mr. Sharon and his aides say a cease-fire pact is not enough, however, that what is needed is to arrest and disarm the militants. What Israelis increasingly say is that the Palestinians need "their own Altalena." Little known to the outside world, the Altalena episode is frequently invoked because without some equivalent, the Palestinian state may never come to be.

In the final years of the British mandate in Palestine, there was not one Jewish militia but several, just as there are competing Palestinian groups today. The main one, the Haganah, was led by Mr. Ben-Gurion. A more violent and radical one, the Irgun Zvai Leumi, often called simply the Irgun, was led by Menachem Begin. The Irgun, along with an even more radical group, the Stern Gang, was responsible for a massacre of more than 200 Palestinians in the village of Deir Yassin in April 1948.

A month later, after the British walked out of Palestine and Mr. Ben-Gurion declared the state of Israel, Arab armies attacked. On June 1, the Haganah and Irgun agreed to merge into the Israel Defense Forces, headed by Haganah commanders. The accord called on Irgun members to hand over arms and terminate separate activity, including arms purchases abroad.

But there remained the question of an old American Navy landing vessel bought by the Irgun's American supporters and renamed the Altalena. The ship, whose purchase had predated the June 1 agreement, was packed with 850 volunteers, 5,000 rifles, 3,000 bombs, 3 million cartridges and hundreds of tons of explosives.

Mr. Ben-Gurion wanted every soldier and bullet he could get and ordered the ship to dock. But Mr. Begin said the arms should go to Irgun troops. Mr. Ben-Gurion refused; at that point, Irgun men headed to the beach to unload the arms.

Mr. Ben-Gurion realized the challenge he faced. As he put it in his memoir, "I decided this must be the moment of truth. Either the government's authority would prevail and we could then proceed to consolidate our military force or the whole concept of nationhood would fall apart."

He ordered the Altalena shelled. Dan Kurzman, in his biography of Mr. Ben-Gurion, "Prophet of Fire," describes the old man sitting with his cabinet just before his decision, "his eyes inflamed from sleeplessness, his hair in even wilder disarray than usual," and saying, "The state can not exist until we have one army and control of that army."

After the volunteers disembarked, Mr. Begin boarded the ship, as did other Irgun fighters. The shelling began. When one hit and the Altalena burst into flames, Mr. Begin was hurled overboard by his men and carried ashore. The ship sank, along with most of its arms and more than a dozen Irgun members. Others were arrested, and the Irgun's independent activities were finally put to an end. "Blessed be the cannon that shelled that ship," Mr. Ben-Gurion declared, providing his political enemies on the right with a rallying cry against him for the next generation.

In his 1953 memoir, "The Revolt," Begin says he had known hunger and sorrow in his life but had wept only twice — once, out of joy, when the state was declared, and the second time, in grief, the night the Altalena was destroyed.

The point for the Palestinians is that until their radical militias are put out of action, those groups will always be in the position of spoilers. In 1996, the Palestinian Authority showed itself capable of confrontation, making widespread arrests of extremists in the wake of several suicide bombings. Thousands of militants were arrested. But most were eventually let go. The Palestinians must do it again and in a definitive manner. The Altalena is a symbol of that task because it involved genuine confrontation yet little loss of life. As Mr. Ben-Gurion wrote in his memoir:

"The incident caused near civil war among the Jews themselves. But in the eyes of the world we had affirmed ourselves as a nation. When the smoke cleared and the indignation died down, the population at large put itself squarely behind its government. The days of private armies were past, and, in the manner of every other well-organized state, we had the makings of a central command under government control."