You missed wide, carp. What six is saying is that a "war" of any kind against something that is so nebulous so hard to define, almost mercury-like is neither possible nor practical. The concept of victory is just that: a concept an idea that has yet to be executed. Cockroaches have evolved and survived for millions of years. Even the most advanced technology has been unable to eradicate the species. Sure, that's a predictable and easy analogy for how we might view terrorists in general. But more so in terms of how to deal with them. Maybe a simpler metaphor is Whack-A-Mole.