The only people who benefit from drugs being illegal are drug dealers. Drugs account for the vast majority of crime and people in prison. Prohibition has never solved anything, people will always find what they want or an alternative. At the moment, despite drugs being illegal, anyone can just go out and buy what ever they want at any time of day. Personally I would legalise all drugs and then the government would get the revenue and more importantly drug gangs would not. The majority of violent crime and ultimately murder is drug gang related. If we only gave it a limited trial the drug gang connections would be shattered – imagine, overnight all their activities would be stopped. We should be giving people a better way of life so that they did not need to resort to drugs.
Adopt the same ideas as Portugal. They have decriminalised use and treat it as a health issue. According to reports (that I have heard on the radio) Portugal's drug problem has reduced significantly.