I'm not a Political Scientist or even particularly well read on the subject. But 'The Clash of civilizations', by Huntington Is a fairly standard big picture view.
https://en.wikipedia.org/wiki/Clash_of_Civilizations
America is unfortunately now immersed in tribalism. Those who should be trying to reverse the trend such as the media and Intellectuals have embraced tribalism as much as the rest. There is no civilisation that can withstand the forces of tribalism.
The breakup of Yugoslavia is an informative example of how a state collapses when ethos is replaced with tribalism.
https://en.wikipedia.org/wiki/Yugoslavia