With the goal of discouraging companies and high net worth individuals from leaving the country to save taxes by taxing wealth leaving the country by a multiple of the taxes due per year if they stayed.
With "state" I mean a sovereign state which nationally can do whatever it wants, I'm only asking about international treaties/laws.
Purely hypothetical question, sorry if this shows a lack of basic understanding on my part. To me it seems like that would be qualitatively similar to the transaction tax some people have been proposing.