What are the motifs in Rainbow Six by Tom Clancy?

Ideological terrorism is a recurring idea in the story. The top-secret Rainbow unit is formed to fight terrorism. They are called in to resolve terrorist/hostage situations in Austria, Switzerland, Spain, England, and Australia. Several of the incidents involve ideological terrorists from the terror network existing before the fall of the Soviet Union. The ideological terrorist is the most difficult to defeat since they, at least in their view, have a cause or belief that has more importance than money or power.