Because they wanted to eat them
In Greek democracy, only male citizens above 18 had true power to vote and have say in government. Today, everybody in the country has that right. There are also some differences in the bodies of governing power, but I don't know too much about them, so I won't say anything because I wouldn't want to give you wrong information. :)
I mean this is your opinion, but i believe it shouldn’t because it’s harming others.
They did not want to get involved in foreign issues and they did not want to start another world war