The first registration writing of the marijuana use was made by the Greek Herodoto in the century V before Christ (9 books of the history). Herodoto counts that the Greeks were very afraid of the Citas, nomadic tribe whose warriors used marijuana before the battles. Under the effect of the drug they had not afraid of anything. When they appeared the Citas killed, they plundered and they raped leaving a death, destruction and terror trace.
The American soldiers are the New Citas ones. Wherever they step the American soldiers kill, they mutilate, they rape and they plunder. They use marijuana (and other drugs), but most of them would not know how to say who was Herodoto. Among the ones that they know Herodoto, few read the 9 Books of the History.
I don't find strange the Americans to use marijuana more and more young. This is part of a new tribal ritual of passage in USA. For if they turn true American soldiers (in other words, for they be transformed in New Citas) they need to know the culture of the marijuana.