There is a huge difference between smugglers and spies though. Profit motive is all you need to be a smuggler, you don’t need espionage or anything else, you definitely don’t need a handler in zhongnanhai.
And by dictionary definition once someone has been established as a smuggler, there’s technically no way they can also be labelled as spies, or engaging in espionage. Also, spies never smuggle, never. Spy’s honour! Yeah, that makes total sense.
> Profit motive is all you need to be a smuggler, you don’t need espionage or anything else
What you need to be a smuggler is to avoid prison.
When one side is fully aware that you are a smuggler that they can rat on to the other side whenever they want, even a child could blackmail you.
So that's one (fairly realistic imo) pathway from smuggler -> to espionage.
This is a hypothetical anyways.