It's Hezb'allah and they are getting assistance from Mexican drug cartels:
Hezbollah is using the same southern narcotics routes that Mexican drug kingpins do to smuggle drugs and people into the United States, reaping money to finance its operations and threatening U.S. national security, current and former U.S. law enforcement, defense and counterterrorism officials say.
The Iran-backed Lebanese group has long been involved in narcotics and human trafficking in South America's tri-border region of Paraguay, Argentina and Brazil. Increasingly, however, it is relying on Mexican narcotics syndicates that control access to transit routes into the U.S.
Hezbollah relies on "the same criminal weapons smugglers, document traffickers and transportation experts as the drug cartels," said Michael Braun, who just retired as assistant administrator and chief of operations at the U.S. Drug Enforcement Administration (DEA).
"They work together," said Mr. Braun. "They rely on the same shadow facilitators. One way or another, they are all connected.
"They'll leverage those relationships to their benefit, to smuggle contraband and humans into the U.S.; in fact, they already are [smuggling]."
US officials think Hezb'allah is more interested in getting cash through drugs and other ventures rather than setting up terrorist operations - at the moment. The point is that they can change that focus in a heartbeat and within a few months, have an infrastructure in place that could wreak terror throughout the country.
Logically, we should be able to kill two birds with one stone by stepping up border security - interdict drugs and stop Hezb'allah from infiltrating America. But that would require the will to do so. And it doesn't appear that there is a will to do much except marginally improve border security while talking about what a wonderful job the government is doing to protect us.
Given the situation around the world, my guess is that we will rue the day we failed to stop Hezb'allah from entering America. They haven't attacked us - yet. But they have the capability and certainly the desire to do so.