I recently gave a shiur on lifnei evar and I came across the article on lifnei evar part two and in it the netziv is brought saying that a Jewish butcher is allowed to sell non kosher meat to a non observant jew because the isur is not taking place right then and there,its only happening later. Is a restaurant different then a butcher? what defines as being there right then and there, is it five minutes or more? Please write where the source is. If there is no problem with selling non kosher meat to non observant Jews, is one allowed to own a non kosher restaurant?
The Netziv relates to the prohibition of mesaye’a, but in opening up a non-kosher restaurant the problem will be more of lifnei iver than of mesaye’a – although concerning selling non-kosher food the prohibition will not generally apply, in the case of a restaurant the situation is different, because each restaurant has its own special nature (depending perhaps on the type of restaurant involved), so that it is hard to say that the same can be obtained elsewhere.
Note also that there is an additional problem of opening up a non-kosher restaurant, namely dealing in non-kosher food (Shulchan Aruch, Yoreh De’ah 117). Although it is permitted to sell non-kosher food on an occasional basis (if one received the food by chance), it is not permitted to deal in non-kosher food on a regular basis.