Updated

A proposal to admit 10,000 Syrian refugees to the United States has ignited a bitter debate in Washington, but more than 10 times that number of people from the embattled country have quietly come to America since 2012, according to figures obtained by FoxNews.com.

Some 102,313 Syrians were granted admission to the U.S. as legal permanent residents or through programs including work, study and tourist visas from 2012 through August of this year, a period which roughly coincides with the devastating civil war that still engulfs the Middle Eastern country. Experts say any fears that terrorists might infiltrate the proposed wave of refugees from United Nations-run camps should be dwarfed by the potential danger already here.

“The sheer number of people arriving on all kinds of visas and with green cards, and possibly U.S. citizenship, makes it impossible for our counterterrorism authorities to keep track of them all, much less prevent them from carrying out attacks or belatedly try to deport them,” said Jessica Vaughan of the Center for Immigration Studies.

“I think it's reasonable to assume that the U.S. Government ran the minimum intelligence traces required at the time of entry."

— Fred Burton, Stratfor

Numbers obtained from the U.S. Customs and Border Protection show 60,010 Syrian visa holders have entered the U.S. since 2012, including 16,245 this year through August. Additional numbers provided by a Congressional source showed another 42,303 Syrians were granted status as lawful permanent residents during the same period.

"It is highly unlikely that the 102,313 Syrians who were admitted over the past three years were effectively vetted," said spokesman Ira Mehlman, of the Federation for American Immigration Reform. "Even in countries where we have a strong diplomatic presence, the sheer volume of background checks being carried out precludes the kind of thorough vetting that is necessary."

The Syrians being admitted are coming directly from their homeland, usually through the U.S. visa program, as opposed to the refugees President Obama is seeking to take in through U.N.-run refugee camps. Most have secured legal entry before they arrive.

"Refugees are part of the admitted category," said Jaime Ruiz, spokesman for the U.S. Customs and Border Protection. "Their cases are approved prior to arriving into the U.S."

Those who escaped Syria’s grinding civil war, which has killed an estimated 300,000, and made it to the U.S. are more likely to be those with the money and means to access the U.S. immigration bureaucracy, say experts. But even that system is susceptible to fraud.

876be1e9-Mideast Jordan Syrian Refugees

Syrian refugees wait for mattresses, blankets and other supplies, and to be assigned to tents at the Zaatari Syrian refugees camp in Mafraq, near the Syrian border with Jordan. (AP)

President Obama’s proposal raised immediate concerns that ISIS, which vowed to infiltrate refugee camps, could use forged documents to enter the U.S. White House assurances that refugees would be carefully screened met with renewed skepticism after it was revealed that terrorist Tashfeen Malik obtained a fiancée visa despite notable red flags. Malik, who together with her husband killed 14 and wounded 21 in a terror attack in San Bernardino, Calif., Dec. 2, listed a phony Pakistani address and reportedly had a history of posting jihadist messages on social media platforms - although FBI Director James Comey disputed that on Wednesday.

Malik’s entry into the U.S., combined with so many Syrians already here, is even more concerning than the proposed refugees, according to Fred Burton, of the global intelligence firm Stratfor.

"I'm more fearful of those currently inside the U.S. predisposed to strike locally as with the San Bernardino model," Burton said. “I think it's reasonable to assume that the U.S. government ran the minimum intelligence traces required at the time of entry."

Mehlman said the same concerns raised in regard to the refugees – mainly that no reliable documents can be issued in a country in complete meltdown – apply to the Syrians already here.

"All civil order has collapsed, and meaningful background checks are impossible,” Mehlman said. “Instead, we rely on cross-checking databases. However, many people with ties to terrorist groups are not in any databases, which means there is no way we can identify them before they arrive here."

A government official who expressed astonishment at such large immigration numbers from a relatively small country, said approximately half are legal permanent residents and the remainder came here on visas, the latter of which remains a point of contentious concern.

Screening of all immigrants and refugees must be tightened, said Rep. Michael McCaul, chairman of the House Homeland Security Committee.

"This administration has forbid our front line security professionals from more broadly incorporating social media information into the visa application process, something that might have kept this attacker out of our country," said McCaul, R-Texas. "We need more robust vetting and screening of all visa applicants.”

Additional data obtained from CBP found that while five Syrians have been apprehended in 2014 and another five in 2015 attempting to cross over the southern border from Mexico, the northern border escapes public and political scrutiny. In 2014 eight Syrians were apprehended by Border Patrol attempting to cross into the U.S. from Canada. Since 2011, 1,229 Syrians have been granted entry from Canada.