The political panic over the admission of Syrian refugees into the United States, following the terrorist attacks in Paris, has unleashed a wave of fear-mongering, bolstered by a notion being propagated by the right wing, that Americans couldn’t possibly know who is being let into our country. Thirty-one U.S. governors have said they won’t accept any Syrian refugees into their state, many of them claiming there’s a large inherent risk in doing so.

Of course, there’s a serious fallacy at work here: By the time any Syrian refugee actually arrives in the United States, we do know who that person is. Very well.

There is a clear difference between refugees in the United States and refugees in Europe, namely that refugees can’t simply walk or use small boats in order to get to the U.S. By contrast, Europe has a flood of humanity getting displaced into their borders, who may enter one of the countries without getting screened — thus creating the danger that even one ISIS terrorist can disguise himself among the people fleeing his cohorts, as French officials believe did occur with at least one attacker.

But the U.S. actually has the advantages of distance and time to pick and choose before anyone from such a faraway land can set foot over here.

That process involves a multitude of complex steps, starting with an initial screening by the U.N. High Commissioner for Refugees, which possibly leads to a referral to the United States and a gauntlet of security checks, personal interviews, medical screening, and matching with a sponsor agency in the U.S. itself. It is far from the mysterious influx of unknown people that the many governors and Republican presidential candidates are making it sound like.

As noted by defense policy researcher Josh Hampson in The Hill: “In fact, there have been no recorded terrorist attacks committed by refugees. The U.S. has admitted 1.5 million refugees from the Middle East since September 11, 2001. The terrorist attacks that have occurred since 9/11 have been committed either by American natives or non-refugee immigrants.”

A State Department spokesperson told The National Memo in a emailed statement:

The United States remains deeply committed to safeguarding the American public from terrorists, just as we are committed to providing refuge to some of the world’s most vulnerable people. We do not believe these goals are mutually exclusive, or that either has to be pursued at the expense of the other. To that end the refugee security screening and vetting process has been significantly enhanced over the past few years. Today, all refugees are subject to the highest level of security checks of any category of traveler to the United States, including the involvement of the National Counterterrorism Center, the FBI’s Terrorist Screening Center, the Department of Homeland Security and the Department of Defense. All refugees, including Syrians, are admitted only after successful completion of this stringent security screening regime.

On a conference call Tuesday, an unnamed senior administration official confirmed to the press that the average time for processing a person through that entire gamut of interviews and background checks takes an average of 18 to 24 months. “As you know, we are trying to look at the process and see if we can make it more efficient without cutting corners on security.”

And yet at a congressional hearing Tuesday, Attorney General Loretta Lynch still had to explain to House Judiciary Committee chairman Bob Goodlatte (R-VA) — who had seized upon recent comments by FBI Director James Comey about the difficulties of the vetting process — that the Justice Department and others in the government do have a “significant and robust screening process in place,” which Europe has not been able to set up.

On Tuesday, Republican presidential frontrunner Donald Trump posted a message to Instagram, with The Donald shouting to the camera with his typical bombast: “Refugees are pouring into our great country from Syria! We don’t even know who they are! They could be ISIS, they could be anybody! What’s our president doing — is he insane?”

And in the Louisiana gubernatorial race, Republican U.S. Sen. David Vitter is running this ad — complete with clips of panic in the streets of Paris — ahead of the election this weekend: “One of the Paris ISIS terrorists entered France posing as a Syrian refugee. Now, Obama’s sending Syrian refugees to Louisiana.”

Newly-crowned House Speaker Paul Ryan (R-WI) is trying to be a bit more low-key, although catering to the same doubts, as he told reporters Tuesday: “This is a moment where it is better to be safe than sorry. So we think the prudent, the responsible thing is to take a pause in this particular aspect of this refugee program in order to verify that terrorists are not trying to infiltrate the refugee population.”

One can perhaps “forgive” Trump for being utterly clueless, and simply expect that Vitter, in the homestretch phase of his campaign, would act like a demagogue. But shouldn’t the Speaker of the House act like he already knows the government has vigorous vetting procedures in place? And for that matter, what does a “pause” even mean when it comes to admitting in refugees who have taken up to two years to be screened?

Refugees, most of them Syrians, struggle to leave a half-sunken catamaran carrying around 150 refugees as it arrives on the Greek island of Lesbos, after crossing part of the Aegean sea from Turkey, October 30, 2015. REUTERS/Giorgos Moutafis