The thing is, Israel needs to worry about its own defense too. Currently there are several semi-hostile neighbors that the US basically pays off, plus the US pays for very expensive defense systems in Israel. Last invasion was long ago, Yom Kippur War, where the US was withholding aid until Israel started losing and suddenly it became an airlift scramble. But more recently there were the two Iran wars where thousands of drones and missiles had to be shot down.
Israel has nuclear weapons. If all their foreign backers pull out they would use them in an invasion scenario, so I dont think they need to worry to much about hot war with a legitimate government.