Fascism is a large and well-studied subject. It has manifested in numerous ways, but has specific material causes. What gives rise to it is capitalist decay, it's an immune system to protect the system, and arises from petty bourgeois consciousness as it trends towards proletarianization. This often involves insular groups and rises in ethnonationalism.

As for countries shifting away from the US, this is already happening in the global south, which is where the US Empire gets its superprofits from. That's why Belt and Road is so dangerous to the US, it builds up infrastructure for south-south trade, which in turn results in development and independence.