Suppose the US attacks Iran. What would be the consequences?
It would galvanize Iranians AGAINST the US, and there really would be even more insistence in Iran to produce a nuclear weapon.
The US could not just depose Saddam, destroy Iraq and get the Hell out, because then Al Qaeda would take over. In the same way, the US could not just remove Amedinejahd and Ayatollah Kalmeinei, because that would leave Iran in a state of anarchy, and whoever took over would certainly NOT be pro-American, For the US to replace Iran's current government with another one that would not be an enemy of the US would be three times as hard as what was done in Iraq: three times the troops, three times the expense, three times as much time, perhaps.
The US cannot afford to do this. We could destroy Iran and perhaps prevent them from producing a bomb for two or three years at most. It would clearly inflate the cost of petroleum, as it would block the Straits would cause a global depression.
Israel is not worth it, and neither is anything else.
If the Iranians are against Israel because they don't want to see the Palestinians suffer for the loss of their land and lives, bombing Israel would kill many Palestinians and render the land useless for a generation. Does anyone seriously think that Iran would bomb Jerusalem?