Your thinking appears to me to be on target... The goal is not to conduct air strikes on Iran, rather, the goal is to prevent Iran from acquiring and using nuclear weapons against Israel. With Israel's very existence at stake, the strategic thinking can not afford to be limited to conventional, direct military engagements.
Unfortunately, the same thing can be said about the threat that the US faces from its Islamofascist adversaries, who will not be constrained by conventional thinking or deterred by traditional means of defense.