“I think if you’re in favor of World War III, you have your candidate,” said Sen. Rand Paul during the Republican debate. He was referring to Gov. Chris Christie, but could have been talking about virtually any of the other eight people standing on the stage at The Venetian.

Indeed, only the libertarian-ish Republican senator from Kentucky was willing to admit that reckless U.S. interventionism in the Middle East—cheered on by Republicans and Democrats alike—gave birth to ISIS. He calmly explained that deposing Saddam Hussein in Iraq and Muammar Gadhafi in Libya created a vacuum for even worse radicals to thrive. And as Paul pointed out, if President Obama and Republican hawks had gotten their wish two years ago and deposed Bashar al-Assad, ISIS would now rule in Syria as well.

While most of the other candidates remained staunchly anti-Russia, anti-Iran, and anti-ISIS—even though the former two are unwaveringly opposed to the latter—Paul was willing to criticize the recklessness of a go-to-war-with-Vladimir-Putin-over-nothing policy.

“If we announce that we’re going to have a no-fly zone… it’s a recipe for disaster,” said Paul. “It’s a recipe for World War III. We don’t need to confront Russia from a position of recklessness that would lead to war.”

Ted Cruz also appeared to realize that regime change in the Middle East was a dangerous game, and Donald Trump was critical of U.S. nation-building—albeit eager to confiscate the oil from the U.S.’s vanquished foes. But only Paul took the principled stance that endless interventionism and anti-Russian posturing actually makes the nation less safe.

Many libertarians (myself included) have been dismayed by Rand Paul’s recent hard-right turn on immigration. But on foreign policy and mass surveillance, he remains the best candidate by a mile. Thank goodness he’s not afraid to make that clear to the American people. (Related: Rand Paul vs. the Libertarian Moment.)