can minors smoke?

Smoke what?

As far as I know, there is no law against a minor smoking. They are merely prohibited from the purchase of tobacco products which is really, really stupid if you ask me. If it is illegal to purchase, it should be illegal to use.

Smoke, Hell . . . they can burst into flame for all i care.

This might depend on the jurisdiction, though in Ontario, as far as I know, there is no law against minors smoking, just against purchasing. However, in highschool I did get suspended for a day for smoking as a "minor" at 15 years old, whereas I was told you must be at least 16 years old. Though that could have been just a school rule, i dunno. Drinking alcohol however, is illegal for minors unless they are under parental supervision I believe.

In the USA, even drinking "under parental supervision" would be illegal in most states for persons under the age of 21. In fact, there have been a number of court cases where the parents were prosecuted for providing alcohol for their teen-age children.

enforced only under extreme circumstances.

I wonder if those cases actually involved parental supervision as opposed to the parents just buying it and letting their kids go party on their own.