Or consider what American computer specialists are doing on the Internet, perhaps terrorist leaders’ greatest safe haven, where they recruit, raise money and plot future attacks on a global scale. American specialists have become especially proficient at forging the onscreen cyber-trademarks used by Al Qaeda to certify its Web statements, and are posting confusing and contradictory orders, some so virulent that young Muslims dabbling in jihadist philosophy, but on the fence about it, might be driven away.

And in a classified tactic used multiple times across the Middle East, American military and intelligence officers have hacked the cellphones of terrorist leaders using computer code, to lure them into an ambush or spread the word that fellow cell members were embezzling money or plotting against their comrades. Distrust of secure communications disrupts and even deters action.

While this new deterrence may not work with suicide bombers once they have strapped on an explosive vest — or Ayman al-Zawahri, Osama bin Laden’s successor atop Al Qaeda — it does with terrorist facilitators like gunrunners, financiers, brokers who find safe houses and many others involved only for personal gain and not to make jihad.

Even terrorists, however suicidal, value some things greatly, like personal glory and their personal reputations.