Americans would support a joint attack on Iran with Israel
According to Rasmussen:
'Fifty-one percent (51%) of U.S. voters believe the United States should help Israel if it attacks Iran.A new Rasmussen Reports national telephone survey finds that 35% say the United States should do nothing in the event of an Israeli attack on Iran, and two percent (2%) think America should help the Iranians.
Support for helping Israel is up nine points from two years ago when just 42% believed the United States should help the Jewish state if it launched an attack on Iran.
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It's unclear, when looking at the question Rasmussen posed, what people take "help" to mean - is it intelligence cooperation, diplomatic cover or an actual joint military operation to strike Iran's nuclear facilities? I would assume it's the last one. A joint Israeli-U.S. military operation against Iran would certainly send many hearts aflutter in Washington, and enrage many in the Middle East. I'd have to think, absent an act of direct Iranian aggression against Israel (of the conventional military kind), such an outcome is all but impossible. It's more likely that the if the U.S. or Israel were to strike Iran, they will do so alone.