Seeing as Hezbollah is a wing of the Pasdaran and Hezbollah has had a known presence on the US-Mexican border since at least 2005 according to FBI director Mueller’s own testimony before Congress, I would hardly call the threat from Iran imaginary and I would advise not decoupling our border insecurity from the Iranian threat. After all, Iran is the world’s foremost sponsor of Jihadist terrorism.
I would also suggest that we ignore our porous northern border at our peril as well. After all, only the good fortune of an alert border guard prevented an attrocity from occurring at LAX in 2000 and that bomb and bomber were coming across from Canada...
Hezbollah is of a totally different purpose and structure than al-Qaeda, otherwise Hezbollah’s sleeper cells would have already struck us hard and often. Hezbollah in the US is Iran’s ultimate instrument of desperate self defense. If we can manage to leave Iran alone, Hezbollah will continue sleeping in the US.
And I think you’re 100% right about the oft forgotten Canadian border.