Hold them to the rule of law. More specifically, when attempts to extradite kidnappers fall on deaf ears, engage Interpol.
See, the kidnappers were CIA. They snatched a German citizen and sent him to be tortured as part of extraordinary rendition. Five months later, they realized they’d fucked up, and brought him back to Europe where they released him on the side of a road in Albania. “Ooops!”
The German government is, understandably, upset. A court in Munich has issued arrest warrants for the 13 agents connected with the kidnapping, but the US has thus far refused to entertain the idea of extraditing them. It’s not hard to imagine how the US would act had one of OUR citizens been treated this way; why they think other countries will accept such behavior is beyond us. “24” is fiction, people.