In May 1967, in brazen violation of previous truce agreements, Egypt ordered U.N. peacekeepers out of the Sinai, marched 120,000 troops to the Israeli border, blockaded the Straits of Tiran (Israel’s southern outlet to the world’s oceans), abruptly signed a military pact with Jordan and, together with Syria, pledged war for the final destruction of Israel.

May ’67 was Israel’s most fearful, desperate month. The country was surrounded and alone. Previous great-power guarantees proved worthless. A plan to test the blockade with a Western flotilla failed for lack of participants. Time was running out. Forced into mass mobilization in order to protect against invasion — and with a military consisting overwhelmingly of civilian reservists — life ground to a halt. The country was dying.

On June 5, Israel launched a preemptive strike on the Egyptian air force, then proceeded to lightning victories on three fronts. The Six-Day War is legend, but less remembered is that, four days earlier, the nationalist opposition (Mena­chem Begin’s Likud precursor) was for the first time ever brought into the government, creating an emergency national-unity coalition.

Everyone understood why. You do not undertake a supremely risky preemptive war without the full participation of a broad coalition representing a national consensus.

Forty-five years later, in the middle of the night of May 7-8, 2012, Prime Minister Benjamin Netanyahu shocked his country by bringing the main opposition party, Kadima, into a national unity government. Shocking because just hours earlier, the Knesset was expediting a bill to call early elections in September.

Why did the high-flying Netanyahu call off elections he was sure to win?

Because for Israelis today, it is May ’67. The dread is not quite as acute: The mood is not despair, just foreboding. Time is running out, but not quite as fast. War is not four days away, but it looms. Israelis today face the greatest threat to their existence — nuclear weapons in the hands of apocalyptic mullahs publicly pledged to Israel’s annihilation — since May ’67. The world is again telling Israelis to do nothing as it looks for a way out. But if such a way is not found — as in ’67 — Israelis know that they will once again have to defend themselves, by themselves.

Such a fateful decision demands a national consensus. By creating the largest coalition in nearly three decades, Netanyahu is establishing the political premise for a preemptive strike, should it come to that. The new government commands an astonishing 94 Knesset seats out of 120, described by one Israeli columnist as a “hundred tons of solid concrete.”

So much for the recent media hype about some great domestic resistance to Netanyahu’s hard line on Iran. Two notable retired intelligence figures were widely covered here for coming out against him. Little noted was that one had been passed over by Netanyahu to be the head of Mossad, while the other had been fired by Netanyahu as Mossad chief (hence the job opening). For centrist Kadima (it pulled Israel out of Gaza) to join a Likud-led coalition whose defense minister is a former Labor prime minister (who once offered half of Jerusalem to Yasser Arafat) is the very definition of national unity — and refutes the popular “Israel is divided” meme. “Everyone is saying the same thing,” explained one Knesset member, “though there may be a difference of tone.”

To be sure, Netanyahu and Kadima’s Shaul Mofaz offered more prosaic reasons for their merger: to mandate national service for now exempt ultra- Orthodox youth, to change the election law to reduce the disproportionate influence of minor parties and to seek negotiations with the Palestinians. But Netanyahu, the first Likud prime minister to recognize Palestinian statehood, did not need Kadima for him to enter peace talks. For two years he’s been waiting for Mahmoud Abbas to show up at the table. Abbas hasn’t. And won’t. Nothing will change on that front.

What does change is Israel’s position vis-a-vis Iran. The wall-to-wall coalition demonstrates Israel’s political readiness to attack, if necessary. (Its military readiness is not in doubt.)

Those counseling Israeli submission, resignation or just endless patience can no longer dismiss Israel’s tough stance as the work of irredeemable right-wingers. Not with a government now representing 78 percent of the country.

Netanyahu forfeited September elections that would have given him four more years in power. He chose instead to form a national coalition that guarantees 18 months of stability — 18 months during which, if the world does not act (whether by diplomacy or otherwise) to stop Iran, Israel will.

And it will not be the work of one man, one party or one ideological faction. As in 1967, it will be the work of a nation.