It's not the UN that's been the problem, it's that UN policy has been driven by the USA, UK, and other aggressively anti-drug governments and agencies. It's put countries that had a tolerant policy, Thailand, India, Columbia, Turkey, Lebanon, Morocco, Nepal, Bangladesh, Pakistan, the list is long, turn 180 because they're all poor developing countries that needed aid. Their governments were bribed by the DEA.
Let's take a moment to say a prayer for the king of Morocco, and the other authoritarian oligarchs that run the country, at least they had the balls to stand up to the UN. All the countries that had long cultural connections with cannabis that gave in and took the dirty money have payed a terrible price. Massive increase in crime and violence, prisons filled with sufferers, huge government and police corruption, in the worst cases decades of civil wars destroying their environment and society.
If the Moroccan government had given in can you imagine the mess it would be in right now? Civil war in the Rif Mountains from the 1960s on, a broken economy, cities filling with homeless hungry people. Hundreds of thousands of people displaced and slaughtered. In hindsight we see who made the right choice telling the UN and it's drug money to go to hell.