ELI5: Explain Like I'm 5

Westphalian sovereignty

Westphalian Sovereignty is a set of rules that say countries should be independent and not controlled by other countries. This means that countries have the right to make their own laws and not have to listen to the laws set by other countries. It also means that countries should not get involved in each other's problems. Each country is like a castle and countries should stay in their own castle and not get involved with the other countries' castles.