Professor Alex Stevens:

The cross-border effects of drug policy decisions are quite interesting but they are very different for decriminalisation and legalisation. There is no particular mechanism by which the decriminalisation of possession in the South would affect people in the North or the rest of the UK. People expressed concern in Portugal that there would be drug tourism, but people do not tend to travel just so they can avoid the risk of punishment, possibly because the risk of punishment is so low. It is different when there is legalisation and there is a market that might attract people. For example, there has long been concern from the neighbours of the Netherlands that people are travelling from Belgium, France and Germany into the Netherlands to buy cannabis that they might take back, so the border regions of those countries might see higher rates of cannabis use than the rest of the country, because they have access to a market. As far as I understand, the citizens' assembly has not recommended legalisation. It has recommended decriminalisation. There is very little by way of a mechanism that would affect cross-Border issues relating to decriminalisation.