Some of that PETN (the explosive that nearly brought down Northwest Airlines Flight 253 in Detroit on Christmas Day) must have seeped into the atmosphere. There's so much cloudy thinking floating around!

It started with Homeland Security chief Janet Napolitano declaring giddily: "the system worked." Before she backtracked. It continued as the Transportation Security Adminstration threw its full bureaucratic gravitas behind a stricter no-peeing and no-blankets rule.

Before they backtracked.

And now half of cable news apparently is convinced: Barack Obama is personally staffing a terrorist-concierge service, welcoming suicide bombers aboard the commercial airliners of their choice.

Still waiting for the backtracking on that one.

Feel free to disagree with this or that administration policy. Maybe some dots weren't fully connected. Maybe the watch lists need to be updated now. But only crazy people believe the new president is secretly with the terrorists. I promise.

Let me say this as plainly as possible: The paranoia is nutty on all sides, and it's never been more loudly broadcast than it is now.

Every day, we learn something new about the kinds of people who wish to harm us. We learn they are tied increasingly to the hardscrabble land of Yemen. We learn they were too good in high school chemistry. We learn, in the case of alleged Nigerian underpants bomber Umar Farouk Abdulmutallab, he's the kind of guy whose match.com profile never gets any hits.

Lonely? Angry? Religious zealot? Next!

But we're getting no useful guidance from all these supposed counterterror experts. They're the ones who are supposed to guide us here. And they're all so smothered in silly political loyalties, they're forgetting the part where they actually say something smart. -- If this is the best we have, Al Qaeda is overestimating us for sure.

All they have to do is wait around. We'll collapse into more muddleheaded thinking, Republicans and Democrats alike.

We'll pass new rules for air travel that won't stop a single terrorist.

We'll thrust the nation into abject fear for all the wrong reasons. From each new close call, we'll learn nothing from any of this at all.

We'll let more PETN float around.

Ellis Henican is a columnist for amNewYork and Newsday and a Fox News contributor.