The Mexican government is expressing some irritation with Texas Gov. Rick Perry, who suggested last week that there’s a "very real possibility that members of Islamic State or other terrorist groups are entering the United States illegally via Mexico." As Perry acknowledged in his own remarks — and as the Pentagon confirmed — "there’s no clear evidence" that this is happening. But as is generally the case when fears of al-Qaeda periodically emerge, a lack of evidence is no barrier to bold sweeping claims.
Intelligence officials have warned for some time that there’s a possibility of terrorists entering the United States from Mexico, and there is indeed some evidence of groups like Hezbollah operating in South America. It would be foolish, then, to completely rule out the possibility that terrorists have crossed into the United States from down Mexico way. But the frequent claims that this is already a major problem are ridiculous.
Last year, for instance, Rep. Louie Gohmert, R-Texas, declared on C-SPAN that "We know al-Qaeda has camps over with the drug cartels on the other side of the Mexican border" and that the group’s operatives are being trained to ‘act Hispanic.’ This claim appears to have been based on essentially nothing.
Also last year, Deroy Murdock, of National Review, argued that "there are at least 7,518 reasons to get the U.S./Mexican border under control." That figure refers to the number of citizens of State Department-listed ‘state sponsors of terrorism’ arrested entering the United States — not just at the Mexican border — in fiscal 2011. More than half of those were from Cuba, a country which is still on the State Department’s list for a variety of reasons but whose immigrant population in the U.S. is not known as a hotbed of jihadist sentiment. (This isn’t to imply that those entering the United States from Syria or Afghanistan are likely terrorists. More likely, they’re fleeing terrorism.)
In 2012, Breitbart.com and a number of other conservative sites claimed that Homeland Security Secretary Janet Napolitano had "admitted" that terrorists enter the U.S. from Mexico "from time to time." The evidence for this supposed admission: what seems like a deliberate misreading of a garbled answer during congressional testimony. (Napolitano hasn’t always helped her own cause on this issue. In 2009 she had to walk back comments that seemed to suggest, falsely, that the Sept. 11, 2001, hijackers had entered the U.S. from Canada.)
The best-documented case of a connection between Middle Eastern terrorism and Mexican drug cartels was facilitated by the U.S. government. Mansour Arbabsiar, an Iranian-American car dealer in Texas, was arrested in 2011, and later convicted, after trying to recruit a Mexican drug cartel to assassinate the Saudi ambassador to the United States. The Obama administration’s allegations that senior Iranian officials were likely in on the plot were met with some skepticism at the time. Whether or not that part of it is true, we do know that no actual Mexican gangs were involved: Arbabsiar’s contact was an undercover Drug Enforcement Agency agent.
The DEA also set up a 2009 bust involving a deal between alleged members of al-Qaeda in the Islamic Maghreb and Colombia’s FARC to smuggle cocaine through West Africa to Europe. This was cited by the agency as evidence of the possibility of an "unholy alliance between South American narco-terrorists and Islamic extremists." This despite the fact that there were never any actual South American narco-terrorists involved and DEA agents had set the whole thing up themselves. This case was also used in Congress to argue for tougher immigration rules — in this case, more scrutiny of travelers from Venezuela.
Again, it’s not outside the realm of possibility that someone planning an attack could sneak over the border. But the scant reports of terrorists trying to enter the U.S. illegally are far outnumbered by the numerous well-documented plots by native-born Americans, naturalized citizens and foreigners entering the country with valid passports and visas.
Border security and counterterrorism are both important issues, but at this point the case for linking them seems pretty weak.
Keating is a staff writer at Slate focusing on international news, social science and related topics. He was previously an editor at Foreign Policy magazine.