Money laundering is like charity
...in the sense that it starts at home:
https://credas.com/news/oecd-money-laundering-leader-board/
I'm sure Vietnam (like many emerging markets) has a problem with the issue, and that the nature of those markets means under-reporting is the norm, but it does seem that the biggest problem is the G7 countries and certain supporting countries who punch above their weight when it comes to laundering (Switzerland, Belgium, Luxembourg).