I believe Israel will overfly whatever nations are necessary without anyone's permission. There are three possibilities:
Israel->Jordan->Iraq->Iran
Israel->Syria->Iraq->Iran
Israel->Saudi Arabia->Iran
Option #3 would only be used if Israel believed the U.S. would fire on Israeli aircraft overflying Iraq.
Hey I pray that the US would not take an aggressive stance against Israel and would render aid and assistance. I am sure the defense ministry would inform the US if they did initiate a pre-emptive strike. I agree whole heartedly that Israel's Defense Force is not to be under estimated. The IAF pilots are amazing.