The Syrian refugee debate has become a national embarrassment. It begins with a president, desperate to deflect attention from the collapse of his foreign policy, retreating to his one safe zone – ad hominem attacks on critics, this time for lack of compassion toward Syrian widows and orphans.

This, without acknowledging his own responsibility for these unfortunate souls becoming widowed and orphaned, displaced and homeless, in the first place. A quarter-million deaths ago, when Bashar al-Assad began making war on his own people, he unleashed his air force and helicopters. They dropped high explosives, nail-filled barrel bombs and chemical weapons on helpless civilians. President Obama lifted not a finger.

We could have stopped the slaughter: cratered Assad’s airfields, taken out his planes, grounded his helicopters and created a nationwide no-fly zone. (We maintained one over Kurdistan from 1991 to 2003.)

At the time, Assad was teetering. His national security headquarters had been bombed. High-level aides were defecting. Military officers were forming a Free Syrian Army.

Against the advice of his top civilian and military aides, Obama refused to intervene. The widows and orphans he now champions are the product of his refusal to do anything that might sully his peacemaking image.

Obama has also charged the Republicans with being afraid to grant admittance to “3-year-old orphans.” He gave zero credit to the very real concern of governors and other officials that terrorists could be embedded amid the refugees. This is no theoretical proposition. At least one of the Paris attackers came to France by way of Greece.

Obama’s own officials have admitted that the absence of thorough data makes it nearly impossible to properly vet Syrian refugees. In response, many Republicans (and some Democrats) urged a pause in admitting Syrians until alternate vetting procedures are developed. In my view, it would have been better to differentiate among the refugees: Admit women, children and the elderly under the current procedures, while subjecting young men of fighting age to far stricter scrutiny.

But Republican candidates have allowed the Syria debate to be derailed into a cul-de-sac on immigration – as if the essence of the Mideast issue is a relatively small number of potential refugees rather than the abject failure of Obama’s policies.

Terror is rising around the world – Sinai, Beirut, Mali, Paris. Brussels was shut down by fear itself. The president, in denial about the collapse of his Syria policy, denounced those demanding a change in course. His secretary of state actually acknowledged a rationale for the slaying of Charlie Hebdo cartoonists for offending Muslim sensibilities with a drawing.

Beyond that is the strategic surrender of the Middle East to Russia and Iran. Which is why, for example, we dare not impose a protective no-fly zone. It’s too dangerous. Russia has filled the Obama vacuum.

Facing a massive failure of seven years of Democratic foreign policy, the Republican candidates have instead tried to outdo each other in being tough on Syrian refugees. This descent into xenophobia was led, as usual, by Donald Trump. He concurred with registering American Muslims, raised alarms about Arab-American treachery (“thousands and thousands” on TV cheering the World Trade Center collapse) and promised not only to deny entry to Syrian refugees, but also to send back the ones already here.

Picture it: Packing them onto his 757, the one with gold-plated seatbelts, then dumping them into a war zone to await the next regime barrel bomb.

Other Republican candidates have issued Trumpian echoes. The Muslim registry had no takers. But some have advocated shutting out all the refugees or taking Christians only. They are chasing the polls showing strong anti-refugee sentiment.

How shortsighted. It may work in the Republican primaries. But Trump-like anti-immigrant, anti-foreigner, now anti-Muslim, anti-Arab rhetoric will not play well in a general election.

John Kasich has forcefully denounced this slide into the swamp. Where are the others?

Charles Krauthammer is a columnist for The Washington Post. He can be contacted at:

letters@charleskrauthammer.com