With the approach of the 40th anniversary of the Yom Kippur War, Israelis are once again reliving the most traumatic of Israel’s wars since the 1948 War of Independence. On Yom Kippur 1973, with the surprise attack on two fronts, we glimpsed our own mortality. Mere hundreds of soldiers defended the line as tens of thousands of Egyptian soldiers poured across the Suez Canal; barely a hundred tanks stood between the Egyptian army and Tel Aviv. On the Golan Heights, the Syrian army nearly broke through to the Galilee.

As soon as the war ended, Israelis began vehemently arguing about what had caused the war. How could we have been so unprepared? How did we ignore the intelligence warnings, the obvious signs of a military build-up along the Suez Canal? Why were army storerooms so understocked?

Religious Israelis wondered about the meaning of a war on the holiest day of the Jewish year. But secular Jews too spoke in a kind of theological language about the “sins” of Israeli society.

After Yom Kippur 1973, we launched a decades-long internal war of atonement. The Israel that we know today was largely born in the aftermath of the Yom Kippur War.

Though West Bank settlements were built immediately after the Six-Day War, they were few and sparsely populated. The settlement movement as an organized force began only after 1973. The decline of the prestige of the governing Labor Party emboldened a new generation of religious Zionists to defy the government and attempt to redraw the borders of the state. Settler leaders spoke of reviving the spirit of 1967 to counter the depression of 1973. And Labor Zionism’s decline – which intensified after the war – convinced religious Zionists that they need to step into the vacuum and revive the fading pioneering ethos.

For its part, the peace movement began to organize in earnest only after Egypt’s president, Anwar Sadat, came to Israel in 1977 – itself a consequence of the Yom Kippur War. Peace activists blamed the Israeli government of the Yom Kippur era for ignoring offers by Sadat to negotiate before he launched his war. They recalled the euphoria among Israelis that followed the 1967 Six-Day War, the sense of Israeli invincibility, the contempt for Arab capabilities. They recalled how Defense Minister Moshe Dayan dismissively said of Arab leaders that he was waiting for their phone call to discuss peace. The Yom Kippur War, left-wingers insisted, could have been prevented had Israel been responsive to Sadat’s overtures. For the first time, significant numbers of Israelis now saw Israel as at least partly, if not largely, responsible for the absence of peace.

For leftwing Israelis, then, the sin of Yom Kippur 1973 was arrogance, an excessive reliance on power. The conclusion was: We must be open to peace and not only rely on power.

For rightwing Israelis, though, the sin of Yom Kippur was complacency, allowing ourselves to believe that the Jewish people no longer faced existential threat. The conclusion was: We must remain alert, never lower our guard.

Each camp created its own historical narrative to vindicate its post-Yom Kippur conclusions. The leftwing narrative traces an arc that begins with Sadat’s unrequited overtures before the war to his 1977 visit to Israel, which confirmed the possibility of peace. But then Israel reverted to its old ways, invading Lebanon in 1982 and massively building settlements in the territories, which led to the first intifada of the late 1980s. Both Lebanon and the intifada, argued the left, confirmed the futility of reliance on power alone.

The rightwing narrative of Israeli history contrasts the victory of 1967, when the Israeli people were united, with the gloom and divisiveness of post-73 Israel. A desperation for peace ultimately resulted in the self-destructive delusion of peace with Yasser Arafat, which literally exploded in our faces during the second intifada of the early 2000s. Finally the defeatist mindset of Yom Kippur led to the unilateral withdrawal from Gaza in 2005. The thousands of rockets that fell on Israeli towns and kibbutzim since then proved the futility of concessions and weakness.

The result of the vehement argument between left and right over the lessons of the Yom Kippur War is that a majority of Israelis became centrists. The left convinced mainstream Israel of the need for territorial concessions for peace. The right convinced it that peace isn’t possible so long as the Arab world rejects Israel’s legitimacy.

The lesson for the Jewish people on the 40th anniversary of the Yom Kippur War is humility. No Jewish group – political or cultural – has all the answers. Each camp has grasped something true, essential, about our predicament; each speaks for a legitimate Jewish value. A healthy people knows how to listen to its own competing voices, sift for insights no matter what their ideological source.

The maturation of Israeli society didn’t happen, though, through dialogue and deep listening but because events forced us to face reality. The first intifada convinced a majority of Israelis of the need to free ourselves from the occupation; the second intifada convinced that same majority of the need to free ourselves from wishful thinking about peace.

Perhaps the most enduring lesson of the Yom Kippur War, then, is the need to lower our guard against each other and listen to competing insights. As we face a year of acute uncertainty, that lesson is especially vital now.