Today I would like to address two of the greatest confusions in the Return of the King. They are quite interconnected: One is Sam’s famous line from the films; “I can’t carry it for you, but I can carry you!”, and the other is the great question, why couldn’t Gwaihir just take the Ring to Mordor?
I will start with Sam’s line. I would like to make it quite clear that nothing of this sort was in the book, so all of the logic I will present here will be for the what-if situation that it was. If you aren’t convinced, then it doesn’t really matter.
The loophole goes that a mouse could’ve had the Ring, while Frodo just carries the mouse, and he wouldn’t be affected. This is absolute nonsense. Frodo would still be affected by the Ring, the mouse would try to escape with the Ring, and Frodo would eventually try to take the Ring from the mouse, possibly much sooner than he ended up succumbing in the end, as he has to watch another bear it with no sign of pain, ’cause you can’t really see those signs in a mouse. Argument completely void.
Now, as for Gwaihir. For those of you who don’t know, Gwaihir is the king of the Eagles, the one who saved Gandalf from Orthanc. Many say he could’ve just carried Frodo to Mount Doom, and the whole series is unnecessary. The thing is, the Eagles are ‘a dangerous machine’ and only come at the bidding of the Valar themselves. If there is another way to do things (within reason), the Eagles will not help you do it. Gwaihir was in Gandalf’s debt from a previous incident, so one may think that maybe he would to repay his debt: No. Gandalf would never ask this of him, and the things Gandalf did ask him to do were relatively low stakes, whereas flying into Mordor during the height of Sauron’s power would be too great a risk. Finally, as Gwaihir himself said, “I can bear you many leagues but not to the ends of the earth.” I think to Mordor from Rivendell would be much too far for Gwaihir to fly with with a hobbit on his back. I hope you now see reason.