Yes, in Europe it would need to be an EU regulation (similar to how any individual US state would not be able to pull it off).
Ships also stop off at multiple countries, so just the US doing this would change quite a bit. The US also loves exercising soft power so this doesn't seem too far off once the EPA is run by someone who wants to protect the environment.
Ships also stop off at multiple countries, so just the US doing this would change quite a bit. The US also loves exercising soft power so this doesn't seem too far off once the EPA is run by someone who wants to protect the environment.