In a post on Saturday at NRO’s the Corner blog, former Bush speech writer Marc Theissen exhibits ignorance of basic security concepts too galling to let pass without comment.

Attempting to refute the idea that hijacking planes and flying them into buildings was “off the table” as a terrorist tactic after 9/11, Theissen says:

Really? Planes were off the table after 9/11? That would come as a surprise to every passenger in the past three years who had their liquids confiscated in an airport security line. Those security measures were instituted because in 2006 we foiled an al-Qaeda plot to hijack airplanes leaving London’s Heathrow airport and blow them up over the Atlantic (a plot our intelligence community says was just weeks from execution).

(First, put aside some issues — “what the government says about its security measures must be true” and both the immediacy and viability of the liquid bomb plot in London.)

The difference between “hijacking” and “bombing” shouldn’t need explaining. The former is taking over the controls of a thing, enabling an attacker to direct it into other things. The latter is exploding something in it or on it so as to render it inoperable.

Americans ritually donate their toothpaste to sanitation departments in the cities they visit not because a liquid bomb could enable the commandeering of a plane, but because the alleged liquid bomb could take a plane out of the sky.

The bombing of a plane is a serious concern, but not as serious or potentially damaging as the commandeering of an aircraft. And commandeering is essentially off the table. The hardening of cockpit doors, new procedures at the fronts of planes, and newfound resolve of passengers and crews against commandeering have reduced the likelihood of future commandeerings to near zero. That was what the plane going down in Pennsylvania was all about.

If it weren’t made in debate about such serious issues, Theissen’s error would be quite comical. In his jumbled version of events, the liquid bomb plotters were going to go to the trouble of capturing the controls of an airplane, then fly it around for a while, and finally blow it up over the Atlantic. It’s reminiscent of the Seinfeld episode in which Elaine attacks the theory that an elderly couple running a nearby cobbler shop had shut it down just to abscond with Jerry’s shoes:

ELAINE (amused): So. Mom and Pop’s plan was to move into the neighborhood…establish trust…for 48 years. And then, run off with Jerry’s sneakers.

KRAMER: Apparently.

ELAINE: Alright, that’s enough of this.