Note: I'm not trying to promote marijuana. I strongly dislike marijuana and cigarettes and I would never use nor recommend either. I'm concerned about health and the awareness of the dangers of drugs.
While browsing questions on Mi Yodeya, I came across this question asking if it's allowed to smoke. The answers ranged from being pretty neutral to totally accepting it:
Igros Moshe wrote that [...] it is not forbidden because "Shomer Psaim Hashem", Hashem guards the fools.
In 1981, R' Moshe wrote that the danger of smoking is no more than the danger of eating unhealthy foods, about which the Rambam does not write that they are "forbidden", just unrecommended.
Binyomin Zilber takes a middle approach, and says that while it may be very unhealthy, yet it would not be intrinsically prohibited[...]
And many more backing themselves with the "Hashem guards the fool" passage.
the answers for this question asking if it's permitted to smoke marijuana took a completely different (and irrational) approach:
Igros Moshe [...] forbids it for several reasons:
1.It damages the body...
2.One gives himself extra cravings, worse than those for food and drink...
3.It is a lack of honoring one's parents, who are no doubt upset by the son's actions.
4.Kdoshim Tiyhe (be holy) is a positive commandment. According to the Ramban, this commandment means not to be "disgusting with the Torah's permission".
(Ironically, this is the same Igros Moshe who said that smoking is not forbidden.) Another answer said the following:
Reb Moshe answers NO you may not smoke marijuana. Here are the list of his reasons:[...]
(Ironically (again), this is the same Reb Moshe who said "the danger of smoking is no more than the danger of eating unhealthy foods" and that said that smoking isn't forbidden but just "unrecommended".)
Nowadays, it's known that the dangers posed by cigarettes is immensely higher than the dangers of marijuana. Cigarettes kill an estimated half a million people a year in the US alone, while marijuana kills zero.[a,b,c] I don't blame them, it's very possible that in those times cigarettes were thought to be way less dangerous than what they actually are, and the opposite with marijuana. So as Curiouser commented, is this position still the same even though we now know the facts? What is the current position in the orthodox community towards cigarettes and marijuana? Has it inverted, or has it remained the same?