Iron dome effectiveness (or lack of it):
out of 460 rockets, Iron dome intercepted just 130. Its only 28%! Now imagine what would happen against actually potent missiles in much greater numbers if Israel attacks Iran? Not a pretty picture.
"Israel's Iron Dome missile interception system continued to fire away on Friday, destroying more than 130 rockets. But Israeli Defense Forces [IDF] said more than 330 rockets from Gaza have landed in Israel since Wednesday. Israel also has been massing tanks along the border with Gaza." Israel, Gaza Continue Rocket Exchanges as Israel Readies Ground Forces
Iron dome intercept missile which are bound to hit protected areas, if system calculate that rocket gonna hit unprotected area system simply ignore it, understand? According to IDF there were ~550 rockets fired from Gaza, 226 where recognized to hit protected areas and countermeasure were activated, 200 of threats were intercepted successfully 26 rockets hit protected areas, simple math will tell you that system is 88 percent effective