Among world leaders today, few hedgehogs are more implacable than Ayatollah Khamenei. Hedgehogs, Berlin argued, “relate everything to a single central vision … a single, universal, organizing principle in terms of which alone all that they are and say has significance.” In this spirit, Khamenei’s organizing principle throughout his 30-year rule as supreme leader has been “resistance” against America.

Rather than calming Iranian national anxieties about the prospect of war with the United States, Khamenei used the word resistance more than 65 times in a recent speech—sometimes more than once in a sentence. “Today in our region,” he said, “the common word among nations is resistance. Everyone agrees with resistance … The recent defeats that the Americans suffered in Iraq, Syria, Lebanon, Palestine and other such countries were an outcome of the resistance of Resistance groups.”

For Khamenei, “resistance” against “global arrogance”—his moniker for American imperialism— is both an ideology and a strategic doctrine. “Resistance,” he said, “unlike surrender, leads to the retreat of the enemy. When the enemy bullies you, if you take a step back, he will undoubtedly advance. The way to stop him from advancing is to resist.” Consistent with Khamenei’s philosophy, Iran has not responded to Trump’s “maximum pressure” campaign with concessions, but rather by sowing chaos in the region and threatening to restart its nuclear program.

Berlin contrasted the dogmatism of hedgehogs with foxes, who, he wrote, “pursue many ends, often unrelated and even contradictory, connected, if at all, only in some de facto way, for some psychological or physiological cause, related to no moral or aesthetic principle.” Even sympathetic observers of Donald Trump’s presidency would likely concur that he pursues contradictory ends motivated by an unknown psychological cause for no clear moral principle. But while Khamenei is the quintessential hedgehog, Trump is a variation on the prototypical fox; he does not know many things as much as he says many things.

Unlike Khamenei’s sole strategic doctrine, Trump’s Iran strategy—sometimes to the left of Glenn Greenwald, and sometimes to the right of Sean Hannity—has had the coherence of a Jackson Pollock painting. Days after angrily tweeting that “If Iran wants to fight, that will be the official end of Iran,” Trump proclaimed that Iran “has a chance to be a great country with the same leadership.” After Iran shot down a U.S. drone over the Persian Gulf this week, Trump ominously tweeted “big mistake.” Moments later, he assessed it may have just been a big misunderstanding. Hours later, he claimed to call off military strikes against Iran 10 minutes before they were to happen.

Trump’s erratic approach—provoking an escalation cycle while simultaneously making clear his aversion to conflict—only increased Tehran’s appetite for risk. As Suzanne Maloney from the Brookings Institution has pointed out, Trump is learning the same hard lesson as six U.S. presidents before him. If Tehran is willing to subject its population to economic hardship and use the entirety of its energy wealth to promulgate an antiquated ideology that advocates “Death to America” rather than “Prosperity for Iranians,” the United States has limited ability—using either engagement or coercion—to dissuade it.