Making treaties with foreign governments and taking care of smuggling across international borders is the federal government's job, and I don't have any problem with them doing it, as long as they're using that power for it's intended purposes.
Indeed. I would also submit that interstate matters must be a federal matter too, though admittedly, the way that occurred (largely) through the commerce clause is quite a stretch- Still, when crime is committed across state lines, there has to be a set of laws to deal with that, no?
If a racketeer can legally exist in one state and cause crimes in surrounding states (wherein his actions are illegal by each state's law respectively) who has the authority for interdiction and prosecution in that case?