The defining conflict of the late 20th century, the Cold War, was all about technology. The emerging conflict against extremist terror may or may not have much to do with technology.

In the developed countries that the extremists are doing their best to terrorize, officials have launched research programs that will in coming years help determine how much of a role advanced technology can have in this struggle. In this three-part report, we consider that very issue from several different angles.

... programmers are writing computer simulations that attempt to model the minds, behavior, and networks of militiamen and terrorists ...

... nine ­terrorist-attack scenarios ...

Spending large sums on counterterrorism is illogical.

Perhaps we should establish a Department of Homeland Vulnerability to publicize our juiciest targets and call for legislation that would make them less attractive.