Europeans are not subject to American laws, but they would be if they stole something in the states, or they would expect to be protected by US police when visi

Europeans are not subject to American laws, but they would be if they stole something in the states, or they would expect to be protected by US police when visiting the states. Can someone with knowledge comment on how this applies to someone engaging in commercial relationship with a US citizen or corporation? I.e. is it fair to make the assumption in that case that their information in the context of that exchange is protected from espionage? If yes, do they have legal resource for breach in this trust or is the right only enforceable by the US citizen or corporation in this relationship?