For young teenagers alcohol and tobacco involve law-breaking, so the answer might not be the one you think, GUEST-1.

But I quite agree that legalising cannabis won't stop the people whose business is making addicts and exploiting them. The compromise which the UK is now trying, in which possession is semi-legal, but it can only be purchased from someone who is dealing illegally, and subject to heavy penalties, is in some ways the worst of all, because it's likely to ensure that the suppliers are multi-drug dealers.

What has to be done is bring about a situation where there is no significant money to be made out of habit-forming drugs. That eliminates the engine that drives the drugs industry, and greatly reduces the damage done to habitual users. It wouldn't solve all the problems, but it would make it possible to start solving them, and reducing them.