Another example would be Jim Jones killing his followers and himself. He was not brave.
Bravery requires having a sense of reality. It is also not usually a word that would describe mass murderers, nor suicide victims.
The reality of these people being at war with us is what I believe the author was trying to convey. Part of their delusion (IMHO) is that the are "soldiers" in some kind of a justifiable war. Understand, the will to perform acts like this make for some dangerous opponnents; I think it would not serve us well to dismiss them as being a bunch rifle dropping, mass surrendering pansies like the WWII Italians.