I love Tolkein. But the unavoidable conclusion of both The Hobbit and the LOTR series, according to the movies, is “just go ahead and start with the eagles and save yourselves a dozen near-death experiences.”
Also: the parallels between LOTR and Europe in the 1930’s and 40’s have been widely noted. Do both stories simply end with Dunkirk? Or, is it, rather, that air power (the eagles) is superior in the end?
timothyone.com 
The eagles only enter Mordor after it was falling. An interesting what if, but inconclusive. They may not have survived Sauron’s strength.
Good point. So I don’t get to create a new Latin phrase: eagles ex machina?