JERUSALEM — Monday morning I was on the phone with Doron Avital, a smart if quirky Knesset back-bencher from the Kadima Party. The announcement that Prime Minister Benjamin Netanyahu’s Likud Party was forming a grand coalition with Kadima was still a day away.

Avital is one of a small group of former commanders of the General Staff Reconnaissance Unit, Sayeret Matkal, Israel’s legendary commando unit. Prime Minister Benjamin Netanyahu was an officer in it; Defense Minister Ehud Barak is a former commander; and the head of Avital’s Kadima Party, Shaul Mofaz, is a former deputy commander.

But as the latter three were plotting to stun Israel with the boldest political move of the decade — canceling the Sept. 4 election and forming a unity government — Avital was still in the dark and getting ready for a primary battle.

“Are you sure you want to do this?’’ I asked him half jokingly. Polls say that if elections were held today, Kadima would only hold on to 11 to 13 seats. That seemed like a lost cause; a loss was likely for Avital.

“The problem with you,’’ he quipped, “is that you read yesterday’s news instead of reading tomorrow’s.” In retrospect, his remark seems prophetic, but he was as surprised by “tomorrow’s news” as I. It was an astonishing announcement.

Mofaz, the head of Kadima, negotiated secretly with Netanyahu and dragged the largest opposition party — in fact, Israel’s largest party — into the coalition. The all-but-formalized decision to go to the polls was canceled at 2 a.m. The ruling government will remain in place for another year and a half. The ruling parliamentary coalition will be the largest in Israel’s history: 94 Knesset members out of 120 are now members of the coalition.

It’s the kind of majority that can do anything; the kind of majority that makes one’s democratic impulses itch. The opposition was not outlawed, but it is totally paralyzed. The coalition can do whatever it wants. It can curb the power of the courts, as some members would very much like it to do. It can provide the prime minister with the backing to strike Iran. It can do nothing. Or it can be a unique opportunity to do some good, to make unusual things happen.

Many Israelis — about 44 percent according to a Channel 10 News poll — woke up Tuesday morning to the news and, after an initial scratching of the head, decided that it was not such a bad idea after all to have a unity government.

The ideological differences between the Likud and the Kadima parties are not great, and having a coalition that is very stable — namely, a coalition in which no party can force the hand of the majority by threatening to quit — might prove beneficial to the public’s greater good.

Israelis have long complained that the electoral system gives too much power to smaller parties of society. They have long protested the ability of shrewd tacticians representing small constituencies (mostly the ultra-Orthodox) to get whatever they want because of their disproportionate amount of power in a system that relies on small parties. They have long yearned for a coalition strong enough to make some necessary painful changes — like getting rid of the arrangement that gives the ultra-Orthodox a pass from military service.

Netanyahu and Mofaz, appearing Tuesday at a joint press conference, promised to do exactly that: they said they would pass a “historic, just and equal solution’’ to the problem of ultra-Orthodox unequal service, they said they would change “the structure of government” to make Israel’s system more stable and less chaotic.

That is an agenda befitting a coalition of such scope. But the proof will be in the pudding: for such coalition to be justified, Avital’s “tomorrow’s news’’ has to also be about reforms and changes. Netanyahu’s scary majority can be justified only if the agenda it promotes is also scary — in scope and ambition.