Necessary but not sufficient.
Weed is a category B drug in the UK: https://en.wikipedia.org/wiki/Cannabis_in_the_United_Kingdom
This means "with penalties for unlicenced dealing, unlicenced production and unlicenced trafficking of up to 14 years in prison, an unlimited fine, or both. The maximum penalty for possession of cannabis is five years in prison and an unlimited fine."
The police absolutely try to enforce this: "In the survey-year ending March 2014, possession of cannabis offences accounted for 67% of all police recorded drug offences in the UK."
Despite this, "In 2017, 7.2% of 16 to 59-year-olds reported using cannabis in the last year, making it the most commonly used illegal drug in the United Kingdom."
If this law, all by itself, was perfectly enforced, the UK would bankrupt itself just on the extra spending in the prison system.
Weed is a category B drug in the UK: https://en.wikipedia.org/wiki/Cannabis_in_the_United_Kingdom
This means "with penalties for unlicenced dealing, unlicenced production and unlicenced trafficking of up to 14 years in prison, an unlimited fine, or both. The maximum penalty for possession of cannabis is five years in prison and an unlimited fine."
The police absolutely try to enforce this: "In the survey-year ending March 2014, possession of cannabis offences accounted for 67% of all police recorded drug offences in the UK."
Despite this, "In 2017, 7.2% of 16 to 59-year-olds reported using cannabis in the last year, making it the most commonly used illegal drug in the United Kingdom."
If this law, all by itself, was perfectly enforced, the UK would bankrupt itself just on the extra spending in the prison system.