Candidates take the stage for the Republican presidential debate at the Ronald Reagan Presidential Library in Simi Valley, Calif. (Frederic J. Brown/AFP/Getty Images)

Judging by the initial media reactions, the second-round Republican presidential debates -- both the undercard and the main events -- were wide-ranging, occasionally substantive affairs. The candidates in both sessions spent a particular amount of time discussing the foreign policy hobgoblins of the present: the meddling of the Kremlin, the perfidy of Iran, the evil of the Islamic State jihadists.

A few of the Republican presidential hopefuls dwelt on a familiar, yet jarring theme: The necessity to recognize that there's a war of civilizations afoot, and that we need to win it.

"This is really about the survival of Western civilization," said Mike Huckabee, referring to the Iran deal, the diplomatic agreement forged between the Islamic Republic and world powers. The Iranians "have sponsored terrorist groups, Hamas and Hezbollah, and they threaten the very essence of Western civilization," he said.

Huckabee, who recently likened the consequences of the deal to the horrors of the Holocaust, was hardly alone. In the earlier debate, Sen. Lindsey Graham (R-S.C.) seemed to conflate the Iranian regime, a Shiite theocracy, with al-Qaeda.

"The worst nightmare in the world is a radical Islamic regime with a weapon of mass destruction," said Graham. "The only reason 3,000 of us died on 9/11 is not 3 million, not 3 million is because they couldn't get the weapons to kill us."

Never mind that Iran had no role in 9/11 (certainly no more than its regional nemesis -- and U.S. ally -- Saudi Arabia). Never mind that Sunni fundamentalist outfits like al-Qaeda and the Islamic State are sworn enemies of the Islamic Republic. Never mind that "radical Islam," in whatever form, is a stateless fringe ideology among the world's hundreds of millions of Muslims.

The candidates needed their bogeyman.

Former Pennsylvania senator Rick Santorum forged ahead, likening Iran to a "death cult," and adding that a majority of Shiites in Iran and Iraq "believe that the end of the world is going to come within their lifetime." There's scholarly debate over whether figures within the clerical establishment in Tehran genuinely believe that, let alone whole populations in the region.

But the most aggressive rhetoric came from an unusual source -- the relatively sober Ohio Governor John Kasich.

He harped on the need to "work with the Western civilization, our friends in Europe" as a reason to abide by the Iran deal for the time being, and later went on to plant his spear in the ground. From the transcript:

Western civilization, all of us, need to wake up to the fact that those murderers and rapists need to be called out, and in Western civilization we need to make it clear that our faith in the Jewish and Christian principles force us to live a life bigger than ourselves ... to make (ph) centers (ph) of justice so that we can battle the radicals, call them out for what they are, and make sure that all of our people feel fulfilled in living in Western civilization....

When referring to "murderers and rapists," Kasich was presumably talking about the Islamic State. But the whole rather incoherent ramble can also be interpreted as dog whistle, demonizing everyone outside the realm of "Jewish and Christian principles" while patting on the back those who subscribe to them.

It's the sort of mentality that underlies the situation where a Muslim student can get arrested for simply bringing in a digital clock he invented to his Texas school.

And it's the sort of messaging we've seen recently from right-wing politicians in Europe like Hungarian Prime Minister Viktor Orban, who has been widely excoriated for his heartless stance on Syrian refugees because of the perceived cultural threat they pose to supposedly Christian nations. (Never mind that hardly any of the beleaguered migrants crossing into Hungary have any desire to remain there.)

Not all in the Republican field toed this line. Kentucky Sen. Rand Paul, known for his libertarian disapproval of foreign interventions, shied away from embracing an existential war overseas. "Sometimes both sides of the civil war are evil, and sometimes intervention makes us less safe," he said, referring to the conflict in Syria.

Donald Trump, for all his spirited braggadocio, didn't fuss much about Iran (beyond calling the deal "one of the worst contracts of any kind I've ever seen") and Muslims, either. He instead pointed to a totalitarian regime that actually has nuclear weapons: North Korea. In this case, the threat wasn't Islam or a civilizational Other, but just North Korean leader Kim Jong Un -- a lone "maniac sitting there," as Trump put it, far too aware of his power.

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