Reflecting on the intellectual and cultural ferment that seized the Arab world in the wake of the shocking defeat of 1967, Hisham Melhem seeks to understand why Arab societies failed to capitalize on this moment and laments “the Arabs’ long descent into the heart of darkness.”

[Immediately after the war], most Arabs sought refuge in denial, refusing to admit that their military rout was emblematic of deeper rotten cultural maladies and social defects and instead calling the disastrous defeat a temporary “setback.” . . . [But] Arab intellectuals and artists . . . transformed Beirut after 1967 into the most lively and cultured city in the Arab world [and] displayed tremendous courage in exposing the entrenched taboos and sacred religious dogmas of Islam and the political myths of the Arab nationalist movement in its Nasserite and Baathist manifestations. . . .

The great intellectual debate in the years after the June 1967 war raged mainly between the progressive current and an assortment of Islamists from many Arab states, who saw the defeat, correctly, as the historic rout of Arab nationalism. There was a faint attempt by some Arab nationalist writers to resuscitate Arabism, but to no avail.

I have always believed that it was only after the 1967 defeat that the Arab Islamists, who were mocked and dismissed by the left in previous decades, began to regroup and reassert themselves intellectually and politically as the only “authentic” alternative to Arab nationalism. None of us who were politically active in those years would have believed that the exclusivist and reactionary Islamists, mainly the Sunni Muslim Brotherhood movement and its various branches, and later the Shiite Hizballah, would dominate Arab life and politics in subsequent decades.

That historic moment of cultural and political ferment and renewal in Beirut began to dissipate in 1973. . . . By that time, . . . the Palestinian national movement, represented by the Palestine Liberation Organization (PLO), had failed to live up to its claim that it represented the genuine “secular” alternative to the humiliated Arab nationalists. The PLO’s blunders in Jordan and Lebanon—in which it intervened in the domestic affairs of both countries and intimidated local communities—deprived the leadership of the pretense that the movement was different from the rest of the Arab regimes.

Two extraordinary events demonstrate something important about Israel’s most fervent adversaries. One was a speech given at something called The People’s Forum (funded generously by Goldman Sachs), which stated, “When the state of Israel is finally destroyed and erased from history, that will be the single most important blow we can give to destroying capitalism and imperialism.”

The suggestion that this tiny state is the linchpin of a global, centuries-old phenomenon like capitalism goes well beyond anything resembling rational criticism. Even if Israel were guilty of genocide, apartheid, and oppression—which of course it is not—it would not follow that its destruction would help end capitalism or imperialism.

The other was an anti-Israel protest that took place in front of New York City’s Memorial Sloan Kettering Cancer Center, deemed “complicit” in Israel’s evils. At organizers’ urging, participants shouted their slogans at kids in the cancer ward, who were watching from the windows. Given Hamas’s indifference toward the lives of Gazan children, such callousness toward non-Palestinian children from Hamas’s Western allies shouldn’t be surprising. The protest—like the abovementioned speech—deliberately conveyed the message that Israel is the ultimate evil and its destruction the ultimate good, cancer patients be damned.

The fact that Israel’s adversaries are almost comically perverse does not mean that they can be dismissed. If its allies fail to understand the obsessive and irrational hatred that it faces, they cannot effectively help it defend itself.