Israel’s victory in the 1967 Six-Day War and its resulting military occupation of the West Bank and its Palestinian residents transformed the Jewish state, providing it with both a measure of security it had not enjoyed and the responsibility of governing a people it did not want. It also transformed Zionism—from an ideology of pragmatism and activism into an ideology of utopianism and passivity.

The stunning defeat of Egypt, Syria, and Jordan, and the sudden expansion of the territory under Israel’s control was ironically a step backward for Zionism, and it has struggled ever since to reconcile its core philosophy with the set of circumstances that has reigned for the past half century. The 50th anniversary of the Six-Day War is an opportunity not only to examine Israel’s past and future trajectory, but also to refashion a more pragmatic Zionism for the next 50 years.

Zionism has always had different strains, from the secular Zionism that predominated in the early years of the movement to the religious Zionism that surged following the Six-Day War. Theodor Herzl’s Zionist vision was the very definition of a utopian fantasy that seemed unachievable: a homeland for a persecuted nation scattered across the globe in a place from which they had been exiled millennia before. That this vision actually came to pass was truly miraculous, but its implementation was anything but a dream. The early Zionists who settled Palestine did not arrive to a Jewish state or even to Jewish self-determination; they arrived to a land controlled first by the Ottomans and then by the British, with little infrastructure or natural resources, and populated by frequently hostile neighbors.

When Israel was born half a century after the first Zionist Congress had called for a Jewish home in Palestine, it emerged directly into a war with its neighbors that resulted in one percent of the new country’s population being killed in the fighting to prevent the new state from being stillborn. The first 19 years of Israel’s existence were marked by struggles to create a viable economy, fend off attacks from the Arab countries surrounding the Jewish state, establish diplomatic ties with the world, and absorb hundreds of thousands of penniless immigrants and refugees.

This was certainly not the fulfillment of Herzl’s utopian vision, laid out in Altneuland, of a prosperous country and harmonious society. But it was the fulfillment of the Zionist essence: Jewish self-determination in the Jewish homeland. That the boundaries of the state in that homeland were limited and that the state was beset by true existential threats presented daily problems for Israel’s governance, but they did not present a threat to Zionism itself. Zionism had become a quest not for the perfect but for the possible, and it was this pragmatism and focus on a single core idea that made Zionism the rare 20th-century ideology that actually delivered on its promise and survived the crucible of wars, upheavals, and Cold War struggles.

The victory in June 1967 changed Israel in ways both momentous and trivial, and it transformed Zionism as well. The Zionist vision that has dominated Israeli politics and society almost without interruption for the past four decades—dating to Menachem Begin’s revolutionary victory in 1977—became a far more expansive and ambitious one that created the dangerous illusion that Israel could have not only the sun, but also the moon and the stars. Accepting Jewish self-determination in the Jewish homeland was no longer sufficient; Israel could now fulfill this core objective in the entire biblical land of Israel. The outcome of the 1967 war provided Zionism with a new sense of territorial achievement as well as a new sense of security. The victory marked the removal of the perpetual sword of Damocles hanging over Israel’s head and represented the end of the era of Arab armies massing on Israel’s borders, constantly threatening to overrun it. The Yom Kippur War in 1973 was the last-gasp effort by Israel’s Arab neighbors to reclaim the dominance they had lost in 1967, but it only proved the permanence of the new system.

The strain of Zionism that was now dominant began to swing back toward its utopian origins, promising a world in which Jewish sovereignty had to make no compromises. The Palestinian non-citizens that Israel now controlled did not put a damper on this newfound exuberance. The ultimate realization of the Zionist dream appeared at hand, one in which Jews were now able to live throughout the entire land of Israel and were free from the existential insecurity that had plagued them ever since the first waves of European Jews migrated to Palestine the century before.

This transformation makes sense given the historical circumstances. The attainment of Greater Israel logically goes along with the construction of a Greater Zionism. But just as the dream of Greater Israel is increasingly hard to reconcile with the reality of Greater Israel, so too is the case for the expansive post-1967 Zionism. The maximalist vision of Zionism may have seemed like a dream come true in the heady aftermath of those legendary six days, but an honest reassessment 50 years later demonstrates that, like most dreams, it only works in an environment where the normal rules of nature do not apply.

The Zionism that envisions complete Jewish sovereignty between the Jordan River and the Mediterranean Sea does not account for the complication of approximately 2.5 million West Bank Palestinians living in a state of limbo while their own legitimate national aspirations go unfulfilled. It does not account for Israel’s isolation within its own region and its increasingly difficult relationships with democratic European allies. It does not account for the security, economic, and ethical strains that controlling the West Bank places upon the Israeli state and society.

That Israel is not solely to blame for this situation, and that Israel cannot neatly or responsibly extricate itself from the West Bank overnight, does not change the fact that the Zionism that has become dominant in the last 50 years has become a slave to its environment rather than a force working to change it.

Part of Zionism’s greatness was its ability to unify, but in shedding its pragmatic and activist spirit, it evinced a new capability to divide. By refusing to acknowledge that a more pragmatic vision is required and that the movement’s founders would not recognize an ideology that is so risk-averse that it has now ossified, Israeli and American Zionists risk the entire enterprise. The expansive vision of Zionism is dangerous in that it has created a set of expectations that cannot be met; by insisting in the face of all evidence and logic that it can overcome these insurmountable obstacles, it is setting itself up for a devastating fall.

One of the lessons to be learned from the events of June 1967 is that Zionism is most successful and dynamic when it seeks to make the best situation out of the circumstances in which it finds itself. For a young country constantly under siege that seized the opportunity to smash its foes, reclaim its holy places, and gain some much needed strategic depth, a Zionism that urges its adherents to settle the land of forefathers and prophets made sense. For the Israel of 2017, it does not.

If Zionism is to remain strong, it cannot support the status quo that has been established. A healthy Zionism must navigate the gap between dreams and reality and adapt to a changed world, one in which Israel can no longer afford to control another people without tearing itself apart, and is also strong and secure enough to not have to exert such control.

The 50th anniversary of Israel’s greatest victory and the apparent realization of Zionism’s greatest desires can be a time for Zionism’s renewal, which means a more pragmatic and realistic ideology that marries ambition with advisability. Governing and statecraft almost always involve tradeoffs, and that means rejecting the 1967 myth that Israel and Zionism can have everything they want, and embracing the truth that Israel and Zionism have to live within their means. Otherwise, one of the most successful political ideologies of the modern age will find itself unnecessarily struggling to maintain its viability.