The idea
It is a fairly substantiated scientific claim that legalising drugs would be beneficial to the country for several reasons:
1) It takes the illegal trade in drugs out of the hands of criminal gangs and into the government
2) The govt makes plenty of money through the sale of tobacco and alcohol, both of which kill far more each year than all illegal drugs combined, why not make a bit of money from legalising the rest
3) Although some are extremely dangerous such as heroin and crack, most illegal drugs are much safer than alcohol. Cannabis is 'healthier' than tobacco and hallucinogenics are almost all completely harmless. Drugs are made illegal not on the basis of scientific fact as they should be, but on political bias.
4) Evidence of the political bias is on blatent show in the farce that was the banning of mephadrone and the resignation of professor Nutt along with various other members of the ACMD
5)Legalising the drugs that people take makes it far easier for them to seek and obtain medical help. It is far easier for someone to get help overcoming addiction if the drug they are addicted to is not illegal to obtain or possess.
6) Portugal is a case study where the possession of most drugs has been legalised and it has witnessed a decline in the number of deaths each year from drugs
I all this not as someone who takes drugs nor wants to in the future and in a perfect world there would be no drugs nor a market for them. However this is not a perfect world and so the correct methods must be used to solve the problem, not subpar methods used because the public perceives them as right. Education, not criminalisation, is way to achieve this and education can only come after decriminalisation of drugs.
Why is it important?
This idea is important as it lies behind so many of the problems of today. The drug business is responsible for many of the gang killings in the UK and it kills many people each year.