JERUSALEM — Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak have turned into the odd couple of Israeli politics in whose hands sits the prospect of an attack on Iran. From opposite political traditions with distinct experiences and worldviews, the two have forged a tight bond, often excluding the rest of the Israeli leadership.

For Mr. Netanyahu, an Iranian nuclear weapon would be the 21st-century equivalent of the Nazi war machine and the Spanish Inquisition — the latest attempt to destroy the Jews. Preventing that is the mission of his life. For Mr. Barak, who spurns talk of a second Holocaust and fear for Israel’s existence, it is a challenge about strategy: “zones of immunity” and “red lines,” the operational details of an assault on Iran’s nuclear facilities.

“All leaders have kitchen cabinets, but Netanyahu and Barak have established a kitchenette of two,” remarked Nahum Barnea, a columnist for the Yediot Aharonot newspaper, in an interview. “They haven’t discussed Iran with the rest of the government in weeks and have convinced themselves there is only one way to deal with Iran — their way.”

A top Israeli official who works closely with both leaders and spoke on the condition of anonymity confirmed that the cabinet had not talked lately about Iran, but noted that detailed and long-standing preparation had gone into the possibility of a military strike. Of the two men, he said: “One views himself as a savior, the other lives for a good operation. They’re a strange pair who have come to appreciate each other. Together they control this issue.”

Mr. Netanyahu is the leader of the right-wing Likud Party and grew up in the revisionist Zionist tradition of maximizing territory, standing up aggressively to Israel’s opponents and rejecting the quasi socialism of David Ben-Gurion, the founding prime minister. Mr. Barak grew up on a collective farm deep within the heart of Labor Zionism, and after a long and decorated military career became chairman of the Labor Party. He served briefly as prime minister before losing popular support and an election to Ariel Sharon in 2001.

“On the surface they appear very different,” commented Daniel Ben-Simon, a left-leaning Labor Party member of Parliament who worked with Mr. Barak. “Netanyahu cannot disconnect Israel from the Holocaust. He sees himself as the prime minister of the Jewish people. Barak is the ultimate Israeli, the prince of Zionism. Many thought Barak would rein in Netanyahu on Iran. Instead he joined with him into a two-man show.”

While many here fear a catastrophe if Israel strikes at Iran, Mr. Barak and Mr. Netanyahu increasingly argue that there may be no other option. Their view is that given a choice between an Iran with nuclear weapons — which they say could use them against Israel directly or through proxies, as well as spur a regional arms race — and the consequences of an attack on Iran before it can go nuclear, the latter is far preferable. There will be a counterattack, they say; people will lose their lives and property will be destroyed. But they say it is the lesser of two evils.

“Rockets will fall on this building, but things would be far worse if Iran got the bomb,” said a top former official who has worked for both men, as he sat in a seaside Tel Aviv hotel lobby.

He added that Mr. Netanyahu and Mr. Barak were “meeting one on one with certain cabinet ministers in order to shape a majority in the 14,” referring to the 14-member security cabinet.

They have known each other a long time and have developed a strong mutual dependence. Mr. Barak’s political career, which once seemed so promising, now relies heavily on his relationship with Mr. Netanyahu. And given Mr. Netanyahu’s limited military experience, without the backing of Mr. Barak, who is seen as a military mastermind, he would have trouble winning support for his policy.

Mr. Barak, 70, was a commander of Mr. Netanyahu, 62, in the elite Sayeret Matkal unit in which they both served in the early 1970s. Both have also grown relatively wealthy in recent years from speeches and consulting when not in government, and both feel they understand American politics especially well.

If they did decide to attack, they would need the backing of a majority of the security cabinet. Most estimates are that they would get that support, although the vote might be as close as 8 to 6. But by keeping the issue off the cabinet’s agenda for now, they could be counting on seeking an 11th-hour vote, when it would be harder for ministers to oppose the attack.

Earlier cabinet meetings offer clues as to why they might be avoiding the issue. In its three years, the cabinet held a number of meetings devoted to Iran, according to top officials who add that defense officials and several ministers opposed military action, at least so far.

“They haven’t done it until now,” a top official who is unenthusiastic about an attack said. “Ask yourself why.”

Iran says its nuclear program is purely for civilian use, although Western powers believe its goal is to produce weapons. Israel points to repeated statements by Iranian leaders calling for its destruction and by Iran’s financing and arming of groups fighting Israel. Still, the United States says that diplomacy and sanctions against Iran’s financial and energy industries need time before military action should be considered.

Mr. Netanyahu’s recent trip to Washington is widely thought to have gained President Obama some of that time, with no attack expected in the next few months.

Both Mr. Netanyahu and Mr. Barak say they will be delighted if pressure on Iran leads it to drop its nuclear program. Neither thinks it likely, however, because of the short time frame as Iran moves its centrifuges underground, beyond Israel’s military ability to destroy them.

Public opinion on the matter is unclear, although Mr. Netanyahu remains very popular and Mr. Barak is widely respected as defense minister. In polls about Iran, different questions produce different results. One poll asked Israelis if they favored an attack without American help and a sizable majority, 63 percent, said no. But another asked whether Israelis considered an attack on Iran riskier than “living in the shadow of an Iranian nuclear bomb” and 65 percent preferred the attack, in keeping with the Netanyahu-Barak argument. Some say it is the unusual combination of Mr. Netanyahu with Mr. Barak that could lead to an attack, and while some are grateful, others are terrified. Meir Dagan, a former head of the Mossad spy agency, has complained that the two leaders cannot be trusted to make the right decision.

Ben Caspit, a political columnist for the Maariv newspaper, a former Likud activist and a harsh critic of Mr. Netanyahu’s, wrote in the paper last weekend that he viewed them as dangerous.

Using Mr. Netanyahu’s nickname, he said: “Bibi is a messianist. He believes with all his soul and every last molecule of his being that he — I don’t quite know how to express it — is King David. He’s not cynical in the least. The cynic here is Barak. The fortunate thing is that Bibi’s a coward. The dangerous thing is that he’s got Barak beside him.”