The Great Eagle Mystery

[Gilthalion]

Another potential hazard for an aerial assault would be the weather itself. If Sauron's arm was long enough to send a storm upon Caradhras, then surely he could whip up a doozy of a storm closer to home. This, combined with the lack of secrecy, the smokes, vapors and ashes from Oroduin, and the Nazgul, crows, and Sauron-knows-what-else, would have almost certainly doomed the mission. Besides, it seems that Manwe sends the Eagles to the rescue AFTER the people have faithfully done what was needful.