Whit only airforce, even USA cannot win the war. Tough it depends its goals, If it is the overthrown the current Irans regime, then USA cannot execute that whit only attacking from air. If we once again compare this to the Kosovo crises, in there the US led alliance was unable to couse any significant damage to Yugoslavian land forces. Yugoslavia had airforces in quite similar phase as Iran does so it wasen't able to intercept the allied attackplanes, only few downed aircrafts whit the good ol' KUB SAM...but whit extremely simple discuising messures the whole VJ was left whit only few tanks destroyed. Iran is far bigger country in al means and Iranian army doesen't have no proplems to hide it's primary forces spreaded all over the mountainous landscape. As in Yugoslavia, US is forced to destroy only civilian infastructure wich opposite it's meaning cannot overthrown Irans political leadership. Not in Iran's case. In Yugoslavia, the hated president Milohcevic was put out of power only afterwards the bombings where stopped.