Over the weekend, Prime Minister Ariel Sharon decided who would not be the new head of the Mossad. He crossed A. off the list - the deputy to outgoing Mossad chief Ephraim Halevy. He erased Maj. Gen. Shlomo Yanai. Already off the list was Maj. Gen. (res.) Amiram Levine, who was deputy to Halevy for a year.

That left two names - Maj. Gen. (res.) Meir Dagan, who has been working closely with Sharon tracking the financing of terror groups, and Hagai Hadass ("the kibbutznik") a former department head of the Mossad. Both had supporters and opponents.

Dagan, who ever since the 2000 elections believed Sharon would keep his promise to name him head of the Mossad, had felt some of the certainty slipping recently. But yesterday Sharon kept the promise.

It is the security appointment of national significance that Sharon alone has made. It reflects his wish, on the eve of an expected American campaign against Iraq, and as Iran and other Arab states build up their stockpiles of weapons of mass destruction, for a combative team at the head of the military-intelligence establishment.

Dagan complements Chief of Staff Moshe Ya'alon. Twelve years ago, after the Iraqi invasion of Kuwait, then brigadier general Dagan was head of operations in the general staff and initiated some far-reaching operations deep inside Iraq. Some were meant for the Paratroops brigade, commanded by then-colonel Ya'alon.

If Sharon had been in charge a decade ago, his natural candidate for the top Mossad job would have been his close friend Moshe Levin, a paratrooper and later Mossad agent. But Levin passed away. A mutual friend of himself and Sharon, Shabtai Shavit, didn't want the job a second time. He remembered something former prime minister Yitzhak Shamir once said - "only goats walk backward."

Shavit backed A. - named by Foreign Report as Ilan Mizrahi - deputy chief of the Mossad, while Sharon's favorite generals, Dan Halutz and Moshe Kaplinski, favored Yanai. But Sharon decided to stick to his initial instinct and give the job to Dagan. A., who had planned to quit immediately if Hadass were appointed, will now stay on the job for at least a few months to help Dagan settle in. The leading internal Mossad candidate for the deputy's job is Y., head of Tevek, the Mossad foreign department.

Dagan's critics call him irresponsible and quick on the trigger - but they'll have to prove that. He was involved in some controversies, but as far as it is known, he had the approval of his commanders - including chief of staff Rafael Eitan and Northern Command major general Yanosh Ben-Gal - when he deceived prime minister and defense minister Menachem Begin in south Lebanon.

An internal inquiry by Military Intelligence, headed by reserve lieutenant colonel Zvi Lanir, investigated how the action was hidden - with the compliance of the the command's intelligence officer - from the general staff intelligence officer. Deputy defense minister Mordechai Zippori pleaded with Begin to investigate, but it was the eve of an election. After the election, then attorney general Yitzhak Zamir decided not to order a criminal probe.

Sharon, who was named defense minister after the scandal, now expects Dagan to shake up the Mossad, and inject large doses of aggression, wiliness, and trickery. Those were Dagan's characteristics, as well as the Mossad's, in earlier days. But Sharon is no longer commander of Unit 101, and Dagan has long since stopped being an active member of the Front to Liberate South Lebanon from Foreigners. His solutions, like mixing Israelis in with Arabs in the Rimon Reconnaissance Regiment, aren't exactly appropriate for a time of Arabs mixed in with Israelis in the Rimon Cafe.

Dagan will now be expected to prove he is still an expert at special operations, as he was known 10, 20, and 30 years ago. Like Sharon, who has a 58 percent disability pension from the defense ministry, Dagan has war wounds that slow him physically - he jokes they prove he does have a spine.

Dagan's nomination needs the approval a committee headed by former Supreme court justice Gavriel Bach, which was set up after Benjamin Netanyahu's flawed nomination of Ronni Bar-On as attorney general. But Dagan is not immune from a petition to the High Court of Justice. Though he was never a Likud activist, he did help Sharon in the 2001 elections against Ehud Barak.

His ideological opponents, whether organized or as individuals, could ask the court for a precedent-setting decision to scotch the appointment. But the court has so far only intervened in such high level appointments when there was a criminal conviction, involvement in criminal proceedings, or suspicion of corruption.

Former public security minister Shlomo Ben-Ami thought about reinstating former inspector general Assaf Hefetz to the job two years ago, but Hefetz helped Barak's campaign, so Ben-Ami backed down. However, Danny Yatom, who also helped the campaign, was named head of the "political-security team" in the prime minister and defense minister's office, a one-time position based on personal trust, and not the head of a national security institution like the police, army, Shin Bet, or Mossad. In the opposite direction, when Uzi Dayan, still in uniform, was named head of the NSC, the court rejected a petition by the Movement for Quality Government in Israel against the appointment, disappointing Shaul Mofaz, then the chief of staff.

Dagan's original name was Huberman, and he is a nephew of the famed 20th century violinist who formed the Israel Philharmonic Orchestra. He lives in Rosh Pina and has been active in public demonstrations against returning the Golan to Syria, and often briefs foreign VIPs on the subject.

In the Yom Kippur War he was a major and studied at the Staff and Command College. Along with a teacher and another student, former Shaked Reconnaissance Regiment commanders Danny Wolf and Amatzia Chen, they took the initiative and joined Sharon's corps in Sinai. The three commandeered two jeeps from Shmuel Gorodish, the Southern Command major general, and gave one to Sharon. They used the other to scout assault routes for the brigades, and to conduct their own raids on Egyptian troops. On one, they outflanked advance officers for Egyptian artillery, who were zeroing in on Sharon's field headquarters.

After the war, Dagan transferred to the armored corps, but believed his chances for promotion were limited. One of his friends comforted him with the prediction that he would end up at least commanding a crops. Dagan indeed was named to head the 188th brigade, and then the 36th corps.

Defense minister Moshe Arens promised to make him a major general - which Yitzhak Rabin did - despite chief of staff Ehud Barak's objections. Barak is now one of those opposed to making Dagan the Mossad chief.

But Defense Minister Benjamin Ben-Eliezer, who worked with Dagan making secret contacts with Lebanese Christians, approves of the appointment. As chairman of the Labor Party, Ben-Eliezer's support will help rebuff charges Dagan's appointment is political.