Here is what President Obama, speaking in Lisbon, had to say about the furor over intrusive and humiliating airport security procedures: "...(I)n the aftermath of the Christmas Day bombing, our TSA personnel are, properly, under enormous pressure to make sure that you don't have somebody slipping on a plane with some sort of explosive device on their persons."

But, unfortunately, the threat comes not only from explosive devices on people, but in people. Our country has not yet experienced the terror of a cavity bomb -- a bomb inserted into the rectum or vagina of a suicide terrorist -- but this is what experts, in and out of government, fear is coming. We've already seen the technique used in the Middle East: Colleagues of an Islamist terrorist named Abdullah Asiri detonated a bomb inserted up his rectum last year by cell phone in an unsuccessful attempt to kill a top Saudi counter-terrorism official.

Three experts I spoke to this weekend -- two of whom are currently serving in government in counter-terrorism capacities -- believe it is only a matter of time before the technique is tried here. "We have nothing in our arsenal that would detect these bombs," one told me. "There is no taboo that we can see against this technique. Suicide is suicide, it doesn't matter how gross it is." I asked one of these experts if the body of the terrorist would actually mitigate the power of the blast, as had apparently happened in Saudi Arabia. "My assumption is that a bomb carried onto an airplane in the anus could be removed in the bathroom and detonated clear of the body," this expert said. "You're dealing with a thin-skinned airplane, so even a detonation of a pound of explosives in the anus could punch a hole."