A bunch of Harvard student groups issue a statement putting the blame for Saturday’s wanton massacre of civilians by Hamas “entirely” on Israel. Russia president Vladimir Putin blames the US, while Republican presidential hopefuls are accusing Iran. Meanwhile, Israel’s defence minister says it is all about the “human animals” in Gaza; Hamas, the group of animals in question, blames the existence of Israel.

When it comes to the deliberate slaughter of civilians, those who pull the trigger are always responsible. Yet collectively, these attempts to assign blame for Saturday’s orgy of violence go to the heart of the problem facing Israel’s new “war management cabinet”, formed on Wednesday with Benny Gantz, an opposition leader and retired general: what comes after crushing Hamas? That is best addressed before the Israeli defence forces send tanks among two million Palestinians in Gaza.

What the Hamas attack proves is that the emerging new Middle East everyone was so excited about just a week ago — the one in which Israel trades and invests with its Arab neighbours — cannot happen without some kind of settlement for the Palestinians, says John Jenkins, a former UK ambassador to Saudi Arabia, Syria, Libya and Myanmar, who also served as a diplomat in Israel. “After this is all done, how do you reinvent a new politics of settlement?” he asked at a London panel on events in Israel held by Chatham House on Wednesday. “I don’t know what the answer is; I just know there will have to be an answer.”

There are two paths typically taken to attempt to solve complex territorial problems such as the Israel-Palestine question. One, the route of absolutes, leads inexorably towards greater violence. The other, involving compromise and self-sacrifice, is messy, politically dangerous to those who execute it and hard to achieve. (The attempt cost former prime minister Yitzak Rabin his life.) Israel, tragically, has been on the bloodier track for at least 15 years, and the blame for how that happened is spread widely.

In one narrative of Gaza, what happened on Saturday was the culmination of a failed Israeli experiment, a kind of test for how Israelis and Palestinians might live side-by-side that was offered by Israel, and spectacularly failed by the Palestinians.

The story begins with Israel’s seizure of the Gaza Strip from Egypt in the 1967 Six-Day War. That was a surprise attack, launched to shore up Israel’s security against an increasingly hostile array of neighbours. From 1993, the Israeli Government gave the Palestinians in Gaza limited self-rule, as a result of the Oslo Accords that Rabin signed. And in 2005, after years of terrorist attacks carried out by groups based in Gaza, Israel “disengaged”, unilaterally evicting Jewish settlers and leaving the Palestinians to rule themselves.

The US and Israel had assumed the moderate Palestinian Authority would take charge. Instead, Gazans elected Hamas, an Islamist militant group committed to the destruction of Israel. Hamas used its new position to further its war on Israel, forcing construction of a wall and a blockade of imports to contain it. On Saturday, that experiment collapsed as Hamas breached the wall in multiple locations and wreaked havoc.

Another Gaza narrative, however, is that by unilaterally disengaging, rather than trying harder to negotiate a settlement after the failed Camp David and so-called Taba talks of 2000 and 2001, Israel’s goal was to park Gaza to one side. That later made it possible to impose measures on the more important West Bank, ignoring Palestinian rights and demands. Rather than a step towards a two-state solution, the 2005 Gaza disengagement enabled its eventual abandonment.

These are not, in reality, alternative accounts. They are simultaneous ones, each filled with partial truths. The Netanyahu Government’s delusion that it could park Gaza and a Palestinian settlement, while imposing whatever it wanted on the West Bank, inevitably led to protests in Jerusalem, and the redeployment of military and intelligence resources to deal with that threat. Hamas took advantage of the vacuum, and the prime minister will in time face a reckoning for the catastrophic security failure that resulted. Hamas will meet its judgment even sooner, with the civilians of Gaza paying the price.

This was not inevitable. It was a path chosen by the blinkered, absolutist decisions of extremists. There have been plenty of Israeli and Palestinian voices calling for restraint over the years; they just were not listened to — and they will struggle even more to be heard now. As Ami Ayalon, the former head of the Israel Security Agency, told France’s Le Figaro this week, the Israeli Government needs to make clear as never before that its dispute is not with Palestinians as a people, but with Hamas as a terrorist organisation.

“We have no choice to destroy the Ezzeddine al-Qassam Brigades [Hamas’s military wing],” Ayalon said. “But we should completely change our policy in order to create a Palestinian partner. Before we even attack, we should say that we want to create a reality in which we will talk with the Palestinians who accept the peace initiatives and who want to discuss with us the reality of two states. But I believe that no Israeli government will agree to do this today.”

It is worth trying. Israel cannot be secure unless it first crushes Hamas as a military threat, and then creates a clear path towards a political settlement that answers to Palestinian, as well as Israeli, interests. How it handles Gaza’s civilians in the coming days and weeks — whether it creates a viable escape route and ensures they have food, water and medical care needed to survive — will play a big role in deciding whether that messy, less violent future is possible.

• Marc Champion is a Bloomberg Opinion columnist covering Europe, Russia and the Middle East. He was previously Istanbul bureau chief for the Wall Street Journal.