It's basically one of the UN treaties and Schengen ones that potentially clash, but that's debated as seen here https://eucrim.eu/articles/legalize-it-opportuni

It's basically one of the UN treaties and Schengen ones that potentially clash, but that's debated as seen here https://eucrim.eu/articles/legalize-it-opportunities-and-challenges-for-the-regulation-of-cannabis-under-european-law/ https://eucrim.eu/articles/legalize-it-opportunities-and-cha...