Tanking also allows for a much greater bomb load. A fighter can take off with a full bomb load and empty tanks, then refuel at altitude before heading on the mission. Without refueling, you have to trade bombs for gas.
If Israel does strike Iran, it will be with the tacit cooperation of some other nation. Probably Jordan and Saudi Arabia.
saudi arabia would love nothing better. It’s a sunni vs. shia thang...with Israel stuck in the middle. No matter what they do, they are going to receive horrendous retaliation, both from the world at large with the US leading the charge, and from the muslims of ALL sects.