Russia doesn't want a strike on Iran. I doubt if that will deter Israel, but I tend to believe that Israel would find it hard to strike without at least tacit US permission. How else could their aircraft cross air space controlled by the US?
If they did attack, with or without a US go-ahead, Iran will be certain to blame the US, fairly enough, since Israel would use US planes and bombs. On the other hand, it would take a lot of guts for an American President to order US planes to shoot down Israeli jets on their way to Iran.