Since the Islamic Republic’s creation in 1979, writes Ray Takeyh, American policymakers have repeatedly erred by trying to play “moderates” vs. “hardliners” while shying away from using—or threatening to use—force. Donald Trump would do well to learn from his predecessors’ failures as well as their successes:

Iran should be treated as a unitary nation-state and not a collection of hardliners and moderates that American policy can manipulate to its advantage. The entire notion of Iranian factionalism must be reconsidered in the aftermath of the 2009 revolt, when the theocratic state purged the reformers from its midst. . . .

The George W. Bush administration provides a good case study in what works and what does not. America’s momentary military triumph in displacing the Taliban and Saddam Hussein unsettled the clerical regime, and Iran quickly suspended its nuclear program in 2003. Bush’s forceful denunciation of states that sponsor terrorism and pursue weapons of mass destruction was well-noted in Tehran. And yet, the administration soon fell into the quagmire of negotiations. By 2005, America set aside its forceful posture and sought to engage Iran in stabilizing Iraq and settling the nuclear issue. An Islamic Republic at ease with its revived fortunes responded by accelerating its nuclear activities and lacerating American forces in Iraq with its lethal Shiite militias.

The next lesson to remember is that the Islamic Republic is not interested in normalizing relations with the United States. For the past four decades, American presidents have hoped that offers of dialogue and the possibility of resumed relations would entice Iran into moderation. . . . The point that many White Houses have missed is that the Islamic Republic is a revolutionary state whose entire identity is invested in its hostility toward the West. For the clerical rulers, resumed relations with America are themselves an existential threat.

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.