Yesterday's terror attack in Jerusalem has made Marwan Barghouti, commander of the Tanzim in the West Bank, the center of attention, with a consensus in the defense establishment saying that his insistence on ignoring the limits set by Palestinian Authority Chairman Yasser Arafat has positioned Barghouti as the main challenger to Arafat's leadership.

But opinion is divided on the significance of that conclusion. The Shin Bet believes that if the current trend of the Tanzim becoming stronger at Arafat's expense continues, Israel will be forced to eventually regard "Barghouti and his cohorts" as a partner for security dialogue with a political tint - agreement for renewal of the political process, though not with a promise to complete those talks to the full satisfaction of the Palestinians.

Defense Minister Benjamin Ben-Eliezer also does not rule out talks with the Tanzim, if it turns out that the armed wing of the ruling Fatah is dictating policy to Arafat, instead of the opposite; but Ben-Eliezer is reluctant to engage less militant leaders of the Tanzim, such as its nominal head, Hussein a-Sheikh. Egyptian feelers meant to arrange a meeting between Ben-Eliezer and Arafat have failed, because the defense minister believes the time is not ripe and because Prime Minister Ariel Sharon opposes any direct contact with him.

Characterizing Barghouti as directly responsible for the attacks could remove any restraints from targeting him for arrest or assassination. As long as he enjoys that immunity, the internal Palestinian political developments have determined the level of terror - upwards - while the developments in the American-Israeli arena have determined the level of response - diminishing it.

Military Intelligence research chief, Brig. Gen. Yossi Kupperwasser, wrote in October 2000, when he was still intelligence officer for the Central Command, that Barghouti would use the violent confrontation with Israel to upgrade his standing all the way to becoming a political threat to Arafat. The Shin Bet now agrees with that assessment.

"The big question is who will control whom," says the secret service, "Arafat over the Tanzim, and therefore the entire territory, including Hamas and Islamic Jihad, or the Tanzim over Arafat." As of now, the balance of power between Arafat and the security services and the Tanzim has the Tanzim growing in strength and the Preventive Security forces, headed by Jibril Rajoub in the West Bank and Mohammed Dahlan in Gaza, waning in influence. Therefore, it will be difficult for Arafat to impose a real cease-fire, as opposed to a brief lull, and even less likely is his ordering a full-scale operation to arrest wanted men and disarm the Tanzim. Even if Barghouti were to agree to end the terror attacks, it will take a while before the order takes effect.

At this point, the Shin Bet is arguing that Israel should not talk to the Tanzim, nor encourage the Americans to open a dialogue with the Tanzim, but as the months go by, Israel may find that it has no alternative, because the Tanzim will be "the least of all evils."

But just as Barghouti disobeys Arafat, many of the local Tanzim commanders may disobey him. Among the organization's many local leaders, some are equally involved in criminal activity as in terrorism, and there are rivalries - between the urban groups, and the rural ones, and refugee camp groups.