ELI5: Explain Like I'm 5

Clash of civilizations

Clash of civilizations is a theory which says that in the future, wars or conflicts are more likely to occur between different cultural or religious groups than between countries. For example, countries with different cultures like Christianity and Islam or countries where some people practice Hinduism and some people practice Buddhism might not get along very well and try to fight each other. This could lead to wars between groups of people instead of just between countries.