Updated

Most of the more than 1,000 jihadists who have poured into Syria to fight alongside Al Qaeda carry passports from North America and Europe, raising the possibility that they could easily bring terror back to the west, according to a key lawmaker who receives regular briefings on the issue.

The prospect is especially chilling given that Al Qaeda-linked fighters in Syria seem determined to use the embattled nation as a haven from which to launch future attacks beyond the region, according to Rep. Mike Rogers, R-Mich., who chairs the House Intelligence Committee.

"The number now exceeds 1,000 western jihadists who have shown up, so they'll have passports, good passports, allows them to travel around Europe, maybe get to the United States," Rogers told Fox News. "That's concerning."

Middle Eastern wars drawing insurgents from around the globe is not new, but Rogers said there appears to be even greater intensity in Syria, where Muslim militants have joined Syrians in a bid to oust President Bashar al-Assad.

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"What we've seen to date, a higher rate of foreign insurgents then we did see in Iraq or Afghanistan," Rogers said. "Which is significant if you think of the time frame and then the height of the Iraq War in about '06 we saw a huge influx of insurgents from all over the world, jihadists who had a pretty passionate commitment."

But the outsiders seem to have a different goal than simply ousting Assad.

"The conflict you hear about among Al- Qaeda affiliates is not them fighting for control in Syria, it's them arguing about: 'Do we do external operations or do we focus more in Syria for the time being?'" Rogers said. "That is a dangerous trend for us indeed."

A recently unsealed terrorism case in North Carolina underscored the growing number of Americans accused of travelling to Syria to fight alongside Islamist groups. Basit Javed Sheikh, who was born in Pakistan but is now a legal permanent resident, is accused of hosting a half-dozen Facebook pages praising the operations of Al Qaeda in Syria, known as al-Nusra. The 29-year-old is accused of providing material support to a terrorist organization.

A new report by Kronos Advisory Group, an independent national security research and intelligence firm, documents the growing number of Dutch citizens traveling to Syria and warns Syria could become a safe haven akin to pre-9/11 Afghanistan. Chief Global Jihad Analyst Ronald Sandee and Kronos Principal Michael S. Smith II, write that it is alarming because Holland has not traditionally been a breeding ground for homegrown extremists.

"When it comes to the number of Salafist Jihadis who have traveled from the West to join the Syrian Jihad, it is difficult to pinpoint a solid figure," they wrote in their report. "Still, it is clear that the influx of Westerners into this jihad theater is unprecedented in both speed and size, with individuals from Europe constituting the largest contingent of Western fighters operating in Syria."

Terrorists hardened on the battlefields of Syria would not even require passports to get into the U.S., if the border with Mexico is not better protected, argued the head of the House Homeland Security Committee, Rep. Michael McCaul, R-Texas. McCaul is sounding the alarm over the Department of Homeland Security's high vacancy rate -- including positions at the border, known as CBP and immigration, known as ICE, because those agencies are charged with keeping terrorists out of the country.

"We're not talking about an agency like HUD or something like that, this is a national security agency, that's 50 percent vacant at the top," McCaul said. "And it signals to me that it must not be a priority for this administration and that's what greatly concerns me, and when it comes to catching terrorists trying to come into this country, that's what homeland security does.

McCaul, who also receives regular briefings on the threat picture, said there is growing concern that the administration's policy of helping the rebels is essentially operating blind, without adequate assurances who the U.S. government is really providing aid to.

"I've talked to intelligence officials that are very concerned about who we are working with," McCaul said. "They're very dangerous actors, they kill Christians, they're very --- they're jihadists - and this alliance deeply disturbs me, that this administration has entered into.

"These jihadists historically have shown the propensity to blow back on us,  particularly if we arm them, and they're trained over there, that, in my judgment, is one of the greatest threats to our security here in the homeland," he added.