“While there is likely some drug use/abuse in almost any yeshiva, and the Roshei Yeshiva are aware of the possibility, the yeshivas I am familiar with would not condone such behavior nor would they allow to come to a situation where there is massive drug use!!!”
It is actually a mix. Some RYs are actually very concerned and have sponsored drug abuse programs; others seem to live in terror that the parents who pay the bills, who think that by sending their kids to a Jewish school they will insure that their kids will avoid negative influences, will find out that there is drug use in the school. And few if any can know what kids are doing when they aren’t being watched. It isn’t condoning, it is denial and lack of knowledge.