The White House used the deadly attack in lower Manhattan this week to re-route the conversation back to President Donald Trump’s travel ban, hinting that the administration may consider adding Uzbekistan ― where perpetrator Sayfullo Habibullaevic Saipov emigrated from ― to the list of targeted countries.

“Look, that’s maybe something that’s looked at, but that isn’t something that we’ve called for at this time, but we certainly haven’t ruled it out,” press secretary Sarah Huckabee Sanders said during Wednesday’s briefing.

A look at recent terror incidents in the U.S. demonstrates, however, that a blanket ban on non-visa holders from Muslim-majority countries (the latest iteration of which was temporarily struck down in federal court last month) wouldn’t have successfully kept the terror threat out of the country, according to experts.

A third of the foreign-born perpetrators of attacks in the past few decades immigrated to the U.S. legally, making the travel ban argument moot because it wouldn’t have stopped people with green cards and visas from coming in. And besides, the threat that someone born abroad will commit an attack on U.S. soil remains minuscule.

“If the death toll from the New York attack doesn’t rise, a total of 3,037 people have been murdered on U.S. soil by 182 foreign-born terrorists from 1975 through October 31, 2017,” Cato Institute immigration policy analyst Alex Nowrasteh wrote on Wednesday. “Of those 182 foreign-born terrorists, 63 initially entered with green cards.”

This means, he added, that those who did enter the country legally have killed about 0.5 percent of all people who have died in terror attacks on U.S. soil carried out by a foreigner.

And although some 1,500 Uzbek nationals have left the country to fight with terror groups in Iraq and Syria, according to a Soufan Center report, the country’s risk of exporting terror remains low. Only three terrorists born in Uzbekistan attempted attacks on U.S. soil between 1975 and 2016, Nowrasteh added, and no one was killed.