If like you say Israel & America has forewarned Russia that their system would be defeated,then why worry about it being supplied? Surely not to protect Russia's air defence systems as you have inferred. I get the impression Dan that you feel Israel is a super power militarily.I might add your not alone by some of the responses I have read here and this will apply to them as well. If by some miracle you think that Israel could possibly put a dent into Russia militarily you need to take two aspirins and put yourself straight to bed.
Riot police line up as fresh migrant protests erupt at Budapest railway station (Reuters)
from the article: Russia to supply Iran with S-300 defense systems