The reason for the southern focus is the 2 million plus folks that sneak in undetected, which is far less then the few thousand that sneak in undetected up north. The biggest hole gets the most attention.
Couple that with the fact that plain old illegal aliens kill more Americans then terrorists and put a much greater economic burden on our country then terrorism does, and you have a very good reason to focus on the southern border.
But, yes, I agree, we can not lose sight of the other 3 borders will trying to contain the southern border.
Yes, but unfortunately the two largest enclaves for the Islamic fundamentalists are in Canada, each within a few miles of our northern borders. None of them in Mexico, Central and South American come close in size and organization as those two. So far we haven't been too successful in getting Canada to cooperate with us in issues regarding those centers.
"The reason for the southern focus is the 2 million plus folks that sneak in undetected, which is far less then the few thousand that sneak in undetected up north. The biggest hole gets the most attention."
Actually the biggest hole is the Canadian border, not just in physical size but in visibility and levels of protection; the southern border just had the greatest flow of illegal immigrants. This is knowledge that our Islamic enemies well know...why try to sneak explosives in on the most protected border when they have so many miles of open borders just a few miles away.