How does the book "The ClashCivilisationsions" apply to the identity perspective?

Have you read the book? Wikipedia has a good article on it, plus there are other sites that explain.

"The Clash of Civilizations (COC) is a hypothesis that people's cultural and religious identities will be the primary source of conflict in the post-Cold War world."
https://en.m.wikipedia.org/wiki/Clash_of_Civilizations