given the essentially unchecked flow of immigrants
coming across the Mexican border every day.
The words missing there are "poor Latin" (immigrants). Coyotes are not stupid and want to be left (more or less) alone and free to conduct their business. They "self-police" themselves by selecting who they carry across the border, choosing:
1. People they can trust not to create problems along the way
2. People that will try to stay out of trouble in the US (if you're successful, you're more likely to try to get your family in as well and recommend the same coyote. If you're caught (specially early on) you might turn them in.
3. People that don't look suspicious (that might be undercover law enforcement, for ex)
And above all, they KNOW that the day a terrorist attack within the US is traced back to them public outrage would make law enforcement come down on them with the heat of 1000 suns and the border would be closed tighter than Scrooges coin purse.
Smuggling in illegal aliens is illegal... but smuggling in terrorists is illegal, dangerous and extremely bad for business.
The same thing applies to drug smugglers as well. Collaborating with terrorism isn't in their best interest.
"poor Latin" immigrants have many disadvantages, which is why they depend on coyotes. Presumably, a terrorist organization could:
* pay well enough that the coyotes would forget their principles
* provision their agents well enough to cross on their own.
Or, leave Mexico aside. Why not Canada? Why not Cuba? via boat from Haiti, landing in some god-forsaken part of Louisiana? I can't accept the proposition that getting into the country presents any serious difficulty for someone with means and motive.
You should check out the borders sometime, both Canadian and Mexican. You're underestimating the difficulty of getting across, even if there were no border agents. It's miles of walking through harsh terrain. You start out in the middle of nowhere, get across, and you're still in the middle of nowhere. Most people are not Bear Grylls. It's far easier to just fake some ids and take a plane, which seems to be what most of the bad guys end up doing.
Hiking for a week or so while covering ~20-30 kilometers per day is hardly beyond a motivated individual. Especially if you have collaborators on the other end, and can arrange being picked up in some remote location.
Well, the Coast Guard has spent considerable time, money, and effort learning how to effectively detect and (if necessary) stop people in boats from getting into the US from Haiti and Cuba- at this point, they're pretty good at it.
Not to say that with sufficient funding and time it wouldn't be completely possible; just that it's not as easy as setting out from Havana and ending up in Miami.
Sneaking into the country's no picnic, no matter how you do it. I've always thought that this fact says a lot about what the places that people who do sneak in must be like.
1. People they can trust not to create problems along the way
2. People that will try to stay out of trouble in the US (if you're successful, you're more likely to try to get your family in as well and recommend the same coyote. If you're caught (specially early on) you might turn them in.
3. People that don't look suspicious (that might be undercover law enforcement, for ex)
And above all, they KNOW that the day a terrorist attack within the US is traced back to them public outrage would make law enforcement come down on them with the heat of 1000 suns and the border would be closed tighter than Scrooges coin purse.
Smuggling in illegal aliens is illegal... but smuggling in terrorists is illegal, dangerous and extremely bad for business.
The same thing applies to drug smugglers as well. Collaborating with terrorism isn't in their best interest.