Within a country, it's preferable to address the crime, not the flow of the money, but what do you do if a foreign government is complicit in the crime? Shouldn't governments do their best to turn away dirty money?
Free flow of capital and trade is one of the best way to deescalate conflict between nations, and is something both sides should restrain from interfering no matter how much they hate each other.
A China-US-type confrontation is much preferable over an Iran-US-type confrontation.
