Thanks for explaining how it works. I knew FBI and marshalls are different. I just didnt know if since it was in a foreign country if the FBI would actualy have jurisdiction but not the Marshall's. But you cleared it up with everything else you said.You don't send Interpol after someone. Interpol doesn't work like that, it's an intelligence sharing/database thing, not an international version of the Marshals. You can notify Interpol of a warrant with international extradition, and they'll pass the info along to the nation the fugitive is believed to be in, but police in that nation actually do the warrant arrest. And also, US Marshal =/= FBI, different agencies.
Generally, they just contact the country he's in and ask for the fugitive to be returned via mutual legal assistance or extradition, depending on the treaty with that particular nation. We actually don't have an extradition treaty with Taiwan.
Depending on the circumstances, the fugitive might get escorted back, or might just be put on a plane with travel papers and a cancelled passport, then picked up at the point of entry by US authorities.