The worst nightmare scenario anyone’s come up with in the War on Terror is the possibility of losing an American city to a loose Russian “suitcase nuke.” Those of us who work within the blast radius of any such attack on the White House have even more reason for concern than most. (For a morbidly fascinating diversion, go here and punch the zipcode of a target near you. 20500 for 1600 Pennsylvania.)

So I was happy to learn about this piece by Richard Miniter, shredding “the myth of the ‘suitcase nuke.’ ” It’s a very convincing combination of analysis and original reporting showing that this particular nightmare is one that shouldn’t disturb our sleep. Miniter’s bottom line:

For now, suitcase-sized nuclear bombs remain in the realm of James Bond movies. Given the limitations of physics and engineering, no nation seems to have invested the time and money to make them. Both U.S. and the USSR built nuclear mines (as well as artillery shells), which were small but hardly portable–and all were dismantled by treaty by 2000. Alexander Lebed’s claims and those of defector Stanislev Lunev were not based on direct observation. The one U.S. official who saw a small nuclear device said it was the size of three footlockers–hardly a suitcase. The desire to obliterate cities is portable–inside the heads of believers–while, thankfully, the nuclear devices to bring that about are not.

Miniter is a dedicated hawk, and thus not someone likely to downplay terror threats unless he’s been convinced on the merits that particular threats, like this one, have been overblown.

How else might Al Qaeda acquire nuclear weapons, the quintessential “Weapons of Mass Destruction”? Transfer by rogue states is extremely unlikely. Both Iraq (pre-Gulf War) and Iran have had chemical and biological weapons and longstanding ties to anti-Israel terror groups, yet neither proved willing to risk transferring those weapons to their terrorist proxies, for fear of an overwhelming response by Israel. The same logic of deterrence applies in spades to nuclear transfers.

What about Al Qaeda developing a nuclear weapon on its own? Even less likely. Even if their homegrown WMD efforts have progressed much past the dog-poisoning stage, making a nuclear bomb still seems to require a dedicated effort by a modern state. Does Al Qaeda have the resources and the brainpower to make that happen? I have my doubts. According to one account, terrorist mastermind Jose Padilla “believed he could separate plutonium from nuclear material by rapidly swinging over his head a bucket filled with fissionable material.”