Everything you said is true. But there is one more point to
consider: at the end of the day, Iran is still their neighbour. If
US promise to occupy Iran and keep the Shia in check indefinitely,
I'm sure most Arab states will agree to let US use their bases for
an attack/invasion. But US priorities change over time, they may
pack up and leave one day and then they are faced with a neighbour
with grudges (payback time).
US definitely has superiority in the air over Iran, but does not
have the ability to invade Iran, which means when the Iranians
retaliate after a US strike (it could be non-conventional,
assymmetric, or suicidal types of attacks), they will likely target
those bases that support the Americans. I think they see the risk
is too great for them (to support the US), even though they
probably hate the Shias more than they hate Jews.
