One thing’s certain: Tuesday’s sudden and dramatic expansion of Israeli Prime Minister Benjamin Netanyahu’s coalition government—he now has the support of 94 Knesset members in the 120-seat house—considerably strengthens Netanyahu’s mandate to take what commentators insist on calling “historic steps.” But it is unclear whether the cooption of Shaul Mofaz and his Kadima faction makes an Israeli preemptive strike against Iran’s nuclear facilities more likely or more remote.

We’ve been here before. Likud’s political coup carries echoes of another fateful moment: the establishment of a national unity government on June 1, 1967, the eve of the Six Day War, when Israel felt threatened by a burgeoning, militant Arab coalition headed by Egypt’s President Gamal Abdel Nasser. Back then, a left-wing government, led by Labor Prime Minister Levi Eshkol, was joined under popular pressure by right-wing parties (Menachem Begin’s Herut and Moshe Dayan’s Rafi) to present a united front mere days before Israel, on June 5, launched its devastating preemptive strike against Egypt.

Eshkol and Dayan could not have been more different. The prime minister was soft-spoken, with a wry sense of humor and European manners. Dayan, on the other hand, was brash, bold, and outspoken. One could only imagine how Eshkol felt when he had to abandon the ministry of defense—following Ben-Gurion’s precedent, the prime minister also claimed for himself what was clearly the Cabinet’s most important portfolio—forced by intense public pressure to hand it over to his polar opposite. But Eshkol made the difficult call for the sake of national security.

Today Israel faces the threat of a nuclear Iran—and the prospect of attacking Iranian nuclear facilities without a green light from Washington. But Mofaz is no Dayan.

The Iranian-born politician is known as “Mr. Zigzag”—the Israeli equivalent of flip-flopper. A former IDF paratroop commander and chief of general staff, back in the early 2000s Mofaz was a Likud stalwart (and defense minister). But he bolted the party, which he had called his “home,” in 2005 for Kadima when he realized he wouldn’t become the head of Likud. Six weeks ago, he was elected by Kadima’s rank and file as the new leader of the party, replacing Tzipi Livni, who had inherited Kadima leadership with the fall of then-Prime Minister Ehud Olmert in 2009.

Just days ago, Mofaz vowed not to join Netanyahu’s “crumbling” government and had publicly called the prime minister “a liar” in whom he had no trust. During the past months, he has been a public and staunch opponent of bombing Iran anytime soon, arguing that the nuclear problem must be resolved by the international community through sanctions and diplomacy. In any case, he argued, there was still substantial time before the military option had to be considered.

And yet now, Mofaz will join Netanyahu and Defense Minister Ehud Barak in a three-man kitchen Cabinet or the fuller eight-man “Inner Cabinet,” where the call of whether or not to launch a military strike against Iran will be decided. Both Netanyahu and Barak are on record as pessimists when it comes to the possibility that sanctions or diplomacy will stop Tehran’s march toward nuclear weapons. Both have made it clear that Israel will have to rely on its armed forces to resolve the problem, whether or not Washington gives Jerusalem a green light.

Thinking in Jerusalem is currently focused on the period between July, when a further round of sanctions against Iran will kick in, and the American presidential elections in November. Netanyahu and Barak believe that President Obama will find it very difficult to punish Israel for attacking Iran’s nuclear facilities just before the elections, since Obama will need the help of Jewish donors and voters, and other supporters of Israel, to win. On the other hand, an Israeli strike after the November elections will incur Obama’s wrath—and, some fear, could translate into sanctions against Israel.

No one knows whether Netanyahu elicited from Mofaz a secret promise to support, or at least a vow not to block, a strike against Iran as the price of his entry into the government, where he will serve as a minister without portfolio. But clearly Netanyahu—recently under attack from a number of senior defense figures, including Yuval Diskin, the former head of Shin Bet and ex-Mossad head Meir Dagan, both of whom oppose attacking Iran at present; and, more mutedly, by current IDF chief of general staff Benny Gantz, who said he doesn’t believe Iran will “go the extra mile” and build a bomb—was clearly happy to have Mofaz on board. With the backing of 94 MKs, Netanyahu will present a far more solid antagonist for Obama or any other external or internal doubting Thomases in the coming months.

Mofaz was eager to join the government. The day before striking the deal, the Cabinet had voted for early general elections, to be held on Sept. 4. Opinion polls had predicted that Netanyahu would triumph and emerge as the only politician able to form a new government. Meanwhile, Kadima was predicted to win fewer than 10 seats, which would have relegated Mofaz to political oblivion. (Currently, Kadima has 28 seats, won by Livni in the 2009 elections.) The opinion polls predicted that the lost Kadima seats would have been divided between Labor, with its current leader Shelly Yachimovich replacing Mofaz as leader of the opposition, and Yair Lapid, a popular journalist and son of former center-right politician Tommy Lapid. At least in the short term, Lapid and Yachimovich are the losers in the Netanyahu-Mofaz coup.

Mofaz and Netanyahu—who was not eager to hold general elections because a recent Supreme Court ruling demanded that the government remove an illegal West Bank settlement by July, which would have embroiled the prime minister in bitter controversy with his right-wing allies—have clearly come out the winners. But the Israeli public, too, may well have gained a genuinely unified government, which is why instant opinion polls suggested that the bulk of Israelis supports the Kadima-Likud alliance.

The public opposed early elections as a waste of money that would have delivered no real change. According to the official coalition deal signed between Mofaz and Netanyahu, the new government will promote legislation that will force the ultra-Orthodox community to, at long last, send its sons to do military or other national service and join the labor market (until now, they have basically lived off state subsidies, paid for by the taxes of the largely secular middle and working classes). Getting the ultra-Orthodox to serve in the army and work has been a basic demand of most Israelis, left and right, for decades.

Netanyahu and Mofaz have also agreed to radically change the Israeli political system, which is based on proportional representation. The system has tended to give small, mainly religious parties too much power and the ability to extort political concessions and financial subsidies from the coalitions in which they almost inevitably participate. (Yet most Israeli political commentators have suggested that Netanyahu will balk at implementing such reform, fearing that next time around, the religious parties will take revenge by preferring Labor or a centrist party to the Likud as their potential coalition partners.)

Lastly, Mofaz and Netanyahu agreed to make concessions to last year’s street protesters, who demanded increased government subsidies in education, housing, and other services. Whether the new coalition will indeed deliver is yet to be seen.

Most Israelis are now thinking about their summer vacations in Europe or their unpaid bills (or both). Not Netanyahu. Last week, Netanyahu buried his 102-year-old father, Benzion Netanyahu, a historian of the Spanish Inquisition and, in the 1930s, a vociferous publicist and prophet warning against the impending Holocaust. In interviews in recent years, the elder Netanyahu loudly decried the Iranian nuclear project as a threat to Israel’s very existence. His son, who has in the past three years repeatedly compared Iranian President Mahmoud Ahmadinejad to Hitler, clearly sees neutralizing the Iranian threat as his historic duty and future legacy. He may well have given his father his word on this.

In 1967, the Eshkol-Dayan coalition was a prelude to war. Was adding Mofaz—and 27 other Kadima members of Knesset—part of Netanyahu’s strategy to carry out a risky mission against a similarly brutal enemy? Stay tuned.