It would be interesting to see if microdosing LSD would lead to any ethical objections to war or violence on the part of the Marines.
I mean, I'm pretty sure the tendency for LSD users to ethically object to war or other offensive violence is exactly why the US decided it should be treated as more dangerous than crystal meth (or perfectly legal drugs like alcohol and tobacco and caffeine) despite there being precisely zero evidence of such danger.
There were, to my knowledge, no scientific studies of this relationship, and anyway it was confounded by the US being in a hugely unpopular war, with the Civil Rights movement making non-violence a popular position among its supporters, and by the fact that there was a draft. Now there's no draft, no war, an all-volunteer military.
Also, back then LSD tended to be used in way higher doses. So even if there was a relationship between large-dose LSD use and anti-violence or anti-war views, that doesn't mean that there'd be a similar connection when microdosing LSD.
Something else to consider is that while in the popular consciousness, LSD is associated with hippies and peacenicks, and psychedelics are also associated with peaceful indigenous peoples around the world, there have been some societies (like the Jivaro) which both used psychedelics and were extremely warlike and violent.
So the connection between psychedelics and anti-violent/anti-war views is far from established. That's why it'd make for a very interesting study.