The cartoonish Iranian assassination plot again focuses attention on our soft underbelly — Mexico. You can see why Iranians would want to hire the services of the drug gangs there; as David Ignatius writes in today’s Post:

But why the use of Mexican drug cartels? U.S. officials say that isn’t as implausible as it sounds. The Iranians don’t have the infrastructure to operate smoothly in the United States. They would want to use proxies, and ones that would give them “deniability.”

And, Lord knows, mass immigration ensures that the Mexican cartels have “the infrastructure to operate smoothly in the United States.”

But would cartel members (real ones, that is) work with Islamic terrorists to carry out attacks in the United States? The Stratfor people don’t think so:

“Any plan to use Mexican drug cartels to carry out attacks against the United States would threaten the very existence of the cartel,” a Stratfor analysis said.

“Mexican drug cartels are already facing challenges – struggling with one another and with the Mexican government for control over transportation routes that will allow them to transit cocaine from South America to the United States. Any foray into international terrorism would be bad for business,” Stratfor said.

I’ve spoken with George Grayson, a specialist in Mexican politics at William and Mary who’s forgotten more about Mexico than most people reading this ever knew, and he agrees that it’s unlikely.

I hope they’re right, but I fear they’re not. The Mexican government has succeeded in decapitating the cartels, opening advancement opportunities for less careful, more reckless killers from middle management who might not be quite as far-sighted as their venerable predecessors. What’s more, our current administration’s supine willingness to lick the boots of our current and former enemies (apologizing for Hiroshima? Really?) is the kind of weakness that might be seen as a green light by thugs and cutthroats the world over. Finally, Hezbollah (an arm of the Iranian state, remember) already has a presence in Mexico and one of its officials is under indictment for a deal to sell stolen U.S. weapons to the FARC in exchange for drugs to be smuggled into the U.S. by Mexican cartels.

In the end, why take the chance? We need more double-fencing on the border, military action to clear out the cartels’ forward operating bases in the U.S., reform or elimination of the Border Crossing Card, and more. If it turns out that the cartels are genuinely afraid of working with terrorists, then all we would have done is curtail illegal immigration and drug smuggling (no small achievement itself). But if the cartels are willing to do business with our Islamist enemies and we don’t do everything we can to clamp down at the border, then our government will bear part of the responsibility when the unnamed Washington restaurant is bombed, or a radiological weapon carried in by drug mules goes off in Tucson, or a suicide killer smuggled across by the Zetas goes on a killing spree at a Jewish summer camp in the Catskills.