Iran is even for Israel a big bite and a long jump. And as Syria gets S-300s right to deny the IAF area access, advanced Russian air defence showing up in Iran as well imo are only a question of time. In fact they are already there. They already have S-20c since 2016 -
LINK - and got provided an advanced command HQ for Iran's AD this year. It is operational since two or three months.
On other news I read that Iran also got S-300 already in 2017. They did not say which version. The latest of it seem to be very capable, non-fully-stealthed aircraft may find it difficult to defeat it. And even stealthed aircraft are whsipered behind raise dhands to be anything but untouchable for latest systems like modern S-300 and S-400.
Or did anyone think the Russians would not try hard to react to the building of the F-35?
Anyhow, striking Iran without massive Americna help might be too much even for Israel these days. Wasn't this in the making some years ago, and failed due to American rejection?