U.S. Air Force F-15E Strike Eagles fly over northern Iraq after conducting airstrikes in Syria.U.S. Air Force / Reuters

Here’s a sampling of what the Republican presidential candidates said about Syria and Iraq at Tuesday night’s debate. Ben Carson declared that Russian President Vladimir Putin “is trying to really spread his influence throughout the Middle East. This is going to be his base. And we have to oppose him there.” Jeb Bush said, “It is tragic that you see Iraq and other countries now talking to Russia. It wasn’t that long ago that Russia had no influence in the region at all. … We have to lead.” Carly Fiorina insisted that, “We must have a no-fly zone in Syria because Russia cannot tell the United States of America where and when to fly our planes.”

Notice a pattern? Five of the candidates on the main stage, and everyone in the GOP’s undercard presidential debate, support a no-fly zone in Syria. Asked why, most of them said some variation of: We need to show Russia who’s boss.

Let’s ponder this. Most experts thought a no-fly zone was a bad idea even before Russia began air strikes in Syria. From a humanitarian perspective, as the Rand Corporation’s Karl Mueller has pointed out, a no-fly zone doesn’t do much good because most Syrians are being killed not by bombs dropped from planes, but by artillery, rockets, missiles, and bullets. To stop that, he writes, you would need not merely a “no-fly” zone that controlled the air, but a “safe zone” that controlled the ground. And “the foremost requirement for such a safe zone would be a large commitment of competent ground forces to protect its borders and police the area.” In September, U.S. CENTCOM Commander Lloyd Austin said much the same thing.

Using such a safe zone to nurture a “moderate” rebel force would also require American ground troops, since someone would have to decide which of Syria’s myriad rebel groups to shelter and which to forcibly expel. The United States might outsource that work to Arab, Turkish, or Kurdish allies, but these allies wouldn’t necessarily choose the same rebels, fighting for the same agenda, as America would.

So to make a safe zone effective, even if Russia weren’t in Syria, you’d need lots of American troops. Had the debate moderators confronted the GOP contenders with this reality on Tuesday, it would have quickly deflated their bravado, since post-George W. Bush Republican foreign policy rests on the premise that the United States can restore order and hegemony in the Middle East without the sacrifice of American lives.

But if a no-fly zone—which, sadly, Hillary Clinton supports too—was dubious before Russia’s intervention, it’s even more dubious now. As Mueller notes, the more such a zone strengthened the non-ISIS rebels seeking to overthrow Syrian President Bashar al-Assad, the more Russia would likely escalate its attacks on those rebels, thus neutralizing whatever benefit America’s intervention provided, while increasing the chances of a military confrontation between Washington and Moscow.

For many in the GOP field, this prospect is an occasion for swagger. “My first phone call would be to Vladimir,” declared Chris Christie last month, “and I’d say to him, ‘Listen, we’re enforcing this no-fly zone. And I mean we’re enforcing it against anyone, including you. So don’t try me. Don’t try me. ‘Cause I’ll do it.’”

This might prompt a reasonable person to ask whether America’s commitment to Syria’s “moderate” rebels is important enough to risk World War III over. After all, those moderates are extremely weak. And in part because of that weakness, some have forged alliances with jihadist groups that, while not ISIS, are at least as hostile to liberal democracy and to the United States as Bashar al-Assad is. The chances that Syria’s moderate rebels could defeat Assad, defeat ISIS, rid themselves of their al-Qaeda-like allies, and create a stable, decent Syria are vanishingly slim.

But for the hawks in the GOP field, this is almost beside the point. The point is to show that America still runs the Middle East. Thus, the fact that Russia is now bombing Syria is not a reason to stay out; it’s a reason to go in.

If this sounds vaguely familiar, it should. It’s a return to the worst mindlessness of the Cold War. In the second half of the last century, the United States sent large quantities of arms into poor countries like Angola, Somalia, and Nicaragua, which posed no serious threat to the United States, to fund rebels and regimes with extremely dubious human-rights records—all to keep those countries out of Russia’s hands. Instead of determining which parts of the world were strategically important enough to the United States to be worth expending blood and treasure for, as the diplomat George Kennan urged, the U.S. decided that preventing Soviet influence was an interest in and of itself. This logic led President Lyndon Johnson to send hundreds of thousands of troops to Vietnam, fueling a war in which millions died, not because almost anybody in his administration thought South Vietnam mattered in and of itself, but because letting it go communist would undermine America’s credibility in Asia and the world.

That’s the logic much of the GOP presidential field has embraced now: If Russia intervenes in Syria and we don’t, then Russia is strong and we’re weak. But you don’t measure a country’s strength by how many bombs it drops, and how many armies it funds, especially when it’s doing so with borrowed money. In the 1970s and 1980s, Russia’s third-world adventures—most disastrously in Afghanistan—drained its treasury, demoralized its people, and hastened its collapse. And its current intervention in Syria, which is already breeding hatred among Sunni Arabs and sparking apparent terrorism against Russian civilians, is unlikely to end well either. Meanwhile, China, America’s foremost competitor for global dominance, avoids entangling itself in far-off civil wars. By contemporary Republican standards, that makes it weak.

On foreign policy, the most serious Republican presidential candidates are the “unserious” ones. The first is Rand Paul, who at Tuesday’s debate noted that President Ronald Reagan, for all his bellicose talk, was extremely reluctant to send U.S. troops to war. The second—may lightning not strike me down—is Donald Trump, who said, “I read about the rebels, nobody even knows who they are. … I don’t like Assad. Who’s going to like Assad? But we have no idea who these people [are], and what they’re going to be, and what they’re going to represent. They may be far worse than Assad. Look at Libya. Look at Iraq. Look at the mess we have after spending $2 trillion, thousands of lives, wounded warriors all over the place.”

Trump is right. The experience of the last 15 years offers little reason to believe that waging a larger war in Syria will make Syria more stable or America more safe. But for most of the GOP presidential contenders, that’s irrelevant. It doesn’t really matter where American foreign policy leads, as long as America leads.

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