Regret Aversion by Proxy: Reefer Madness Edition

Via Emily Skarbek, we're treated to a lengthy screed on the perils of marijuana penned by Peter Hitchens. You can safely skip the front matter; the moral argument is wrapped up in the concluding paragraph:

I cannot answer these questions for you, though I know perfectly well what my answer is. I can only say that the conservative mind must surely be sympathetic to the use of law to protect the young from danger, even from themselves and from their own selfishness, which is always at its height during the perilous years of adolescence that so many of us come to regret so much. If it makes us new enemies, even on our own side, to say so, we should be blithely happy to take the burden. Which of the two sides, if it turns out to have been wrong about this great and pressing issue, will have more to regret 20 or 30 years from now?

Regret aversion by proxy, with no mention of externalities. Public policy for private risks. Weed isn't dangerous because you're likely to ram a bus into a crowded convent, but because, "unlike tobacco, its main threat is to the brain and the mind rather than to the heart or lungs."

I guess I don't own my brain. Attlee would be proud.