Peter Bergen is CNN's national security analyst, a vice president at New America, a professor of practice at Arizona State University and the author of "Manhunt: The Ten-Year Search for bin Laden from 9/11 to Abbottabad."

(CNN) In a memorable televised spat in the Oval Office on Tuesday, President Donald Trump met with Democratic Congressional leaders Nancy Pelosi and Chuck Schumer to discuss funding for the border wall and the possibility of a government shutdown.

During the meeting , President Trump claimed that "10 terrorists" were caught at the southern border in a "short period of time."

A query that I sent to the US Department of Homeland Security (DHS) about the cases of the 10 arrested terrorists that President Trump referred to went unanswered.

The number cited by Trump seems to be a garbled version of an assertion by Secretary of Homeland Security Kirstjen Nielsen, who stated , "on average, my department now blocks 10 known or suspected terrorists a day from traveling to or attempting to enter the United States."

The main terror watch list, known as Terrorist Identities Datamart Environment (TIDE), consists of some 1.6 million people with suspected ties to terrorism.

But, of course, there is a big difference between being merely suspected of having some kind of putative connection to terrorism and actually being a terrorist.

In the 450 cases of jihadist terrorism in the United States since 9/11, tracked by the research institution New America, not one involved a terrorist crossing the southern border into the United States. Indeed, if a real jihadist terrorist were ever arrested at the southern border, wouldn't he be put in prison rather than being released to fight another day? And there is no evidence that any such terrorists crossing the southern border have ever been indicted or convicted of a crime.

The terrorists who have infiltrated the United States overwhelmingly did so by taking flights into the country. This is, for example, how Faisal Shahzad entered the country, after being trained by the Pakistan Taliban. Shahzad tried unsuccessfully to detonate a bomb in an SUV in Times Square on May 1, 2010.

In any event, the vast majority of jihadist terrorism cases in the United States -- 84% of them -- were carried out by American citizens or permanent residents who didn't need to infiltrate the southern border, or any border.

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Indeed, every lethal act of jihadist terrorism in the United States since 9/11 has been carried out by an American citizen or legal resident

If the border wall is supposed to ameliorate the issue of terrorism, it's pretty simple: It won't.