I understand that addiction is a difficult matter to overcome and I think the evidence is pretty clear that nicotine is addictive. As such, I agree with the prevailing wisdom that the best strategy for reducing the prevalence of smoking is to prevent teenagers from ever gaining the habit.
In considering possible approaches to this, I am not in favor of sweeping regulation that would outlaw smoking (such regulation could never be passed anyway) and cripple an entire industry that employs many. Often times, new regulations create an enforcement conundrum that cannot be overcome without more funds than the regulations were designed to save. Frankly, that would likely be the case with any all-out ban on smoking. Here's my suggestion.
We know from extensive research that the major reason (practically the only reason) anyone begins smoking cigarettes is to embrace an association with independence, adulthood, and rebellious maturity. How about an economically-innocuous law that requires cigarettes sold in the US must be orange (or bright lime green, or obviously "uncool" in some other physical characteristic). I suspect that such symbols of disparagement might drag fewer teens, desperate to add some trace of hipness to their persona, to the rebellious brotherhood of smokers. If we could focus the public imagination on just how uncool smoking is, and pass on a little well-meaning mockery toward those who choose to do it, I think we could knock down the adoption rate a bit.
I guess what I am saying is that people who want to smoke (or are addicted to nicotine) will certainly smoke. But let's not allow the enduring image that smoking is cool to continue attracting teens to the tobacco lifestyle.