The answer is, they comprehend, and don't care.
Nations mean nothing. Life means nothing. They will martyr whole populations if necessary. People are cannon fodder. They care nothing for any particular nation. When the heat rises, they will disappear to the Sudan, or Indonesia or anywhere, and start again. We either kill them, or identify and destroy their hope. What is of value, something they really care about.
Mecca and Medina?