Neoconservatives believe in a Clash of Civilizations? Since when?
Since always. I recall it being a popular Neocon talking point post 9/11, and one of the reasons given for why we must invade Iraq and Iran.
Have you forgotten all the Neocon war drums calling for war against Iran in the mid 2000s?
One Neocon eventually published a book with that title, in 2011, The Clash of Civilizations and the Remaking of World Order.