Aut dedere aut judicare

Okay, so when two countries make a promise to each other about catching bad guys, they might say "aut dedere aut judicare." This means that if one country catches a bad guy who did something wrong in the other country, they have to either give that person up to the other country to be punished there or they have to punish the bad guy themselves. It's like sharing a toy - if you borrow it and break it, you have to either fix it or give the owner a new one. This is a way to make sure that people who do bad things don't get away with it just because they run away to another country.