I think that the use of illicit drugs is wrong. However i agree with spitfire88 on saying that if the person/user wants to consume those substances, then the government should not be able to deny the right to consume them.
However, if drugs were legalized, then there could be a huge increase in misuse and abuse. while your arguments are valid here is another viewpoint. the point of government is to protect the public. addicts will do lots of horrible things to get there fix. so making drugs illegal helps prevent addicts from hurting others to get their fix. just laws by themselves won't stop this. that is why there are police. still that in itself isn't the only reason. again on the same topic of giving up rights to ensure more rights for more people. Countries whether allies or not are constantly competing to be the best at everything. drugs simply put do not make you smarter.
The vast majority of illegal drugs were first developed to be used as genuine medicines. For example, cocaine was developed as an anaesthetic to be used for surgery. Over time, people realise the good effects these drugs can have and are likely to begin abusing them.