[Ibrîniðilpathânezel]

Originally Posted by Morthoron

Remember, it was Manwë and Nienna who chose Olorin over his objections, and it seems likely that it was Manwë who chose to ressurrect Gandalf after his battle with the Balrog, thereby directly influencing the final outcome of the War.

On the matter of who chose to resurrect Gandalf, Tolkien was explicit: it was Eru.

from Letter 156:

In the end before he departs for ever he sums himself up: 'I was the enemy of Sauron.' He might have added: 'for that purpose I was sent to Middle-earth.' But by that he would at the end have meant more than at the beginning. He was sent by a mere prudent plan of the angelic Valar or governors; but Authority had taken up this plan and enlarged it, at the moment of its failure. 'Naked I was sent back -- for a brief time, until me task is done.' Sent back by whom, and whence? Not by the 'gods' [Valar] whose business is only with this embodied world and its time; for he passed 'out of thought and time.'

Elsewhere, Tolkien makes it clear that "Authority" means Eru, and that "out of thought and time" does not mean back to Valinor, because even though it is no longer a part of the physical planet, it still exists within Time and must, until the End. Earlier in the same letter, he says:

But G. [Gandalf] is not, of course, a human being (Man or Hobbit). THere are naturally no precise modern terms to say what he was. I would venture to say that he was an incarnate 'angel' ... an emissary from the Lords of the West, sent to Middle-earth, as the great crisis of Sauron loomed on the horizon. By 'incarnate' I mean they were embodied in physical bodies capable of pain, and weariness, and of afflicting the spirit with physical fear, and of being 'killed', though supported by the angelic spirit they might endure long, and only show slowly the wearing of care and labour.

Why they should take such a form is bound up with the 'mythology' of the 'angelic' Powers of the world of this fable. At this point in the fabulous history the purpose was precisely to limit and hinder their exhibition of 'power' on the physical plane, and so that they should do what they were primarily sent for: train, advise, instruct, arouse the hearts and minds of those threatened by Sauron to a resistance with their own strengths; and not just to do the job for them. They thus appeared as 'old' sage figures. But in this 'mythology' all the 'angelic' powers concerned with thise world were capable of many degrees of error and failing between the absolute Satanic rebellion and evil of Morgoth and his satellite Sauron, and the faineance of some of the other higher powers or 'gods'. The 'wizards' were not exempt, indeed being incarnate were more likely to stray, or err. Gandalf alone fully passes the tests, on a moral plan anyway (he makes mistakes of jugdement). For in his condition, it was for him a sacrifice to perish on the Bridge in defence of his companions, less perhaps than for a mortal Man or Hobbit, since he had far greater inner power than they; but also more, since it was a humbling and abnegation of himself in conformity to 'the Rules': for all he could know at that moment, he was the only person who could direct the resistance to Sauron successfully, and all his mission was vain. He was handing over to the Authority that ordained the Rules, and giving up personal hope of success.

That I should say is what the Authority wished, as a set-off to Saruman. The 'wizards,' as such, had failed; or if you like: the crisis had become too grave and needed an enhancement of power. So Gandalf sacrificed himself, was accepted, and enhanced, and returned.

Between this and the essay on the Istari in UT, I think Tolkien makes it quite clear that though the Valar feel they cannot become directly involved in the matters in ME, they are still certainly concerned and paying attention to what happens there. Even Eru himself is not above a little bit of off-stage meddling, as he is the one who sends Gandalf back after death, and in an enhanced condition better suited to the needs of the job. I don't think that Manwe directly told any of the eagles in ME to go to a specific place at a specific time, but I do think he might have "nudged" them, given them a feeling to head in a certain direction, where they might be at the right place in the right time. He cannot interfere with their choice, but like Ulmo, he could "whisper," and the whispers had a chance of leading to positive results, if the one who hears chooses to listen, and act. Also, I don't quite think it's the same to compare them to the Eagles of the First Age, since there is some question as to whether or not Thorondor was actually an Eagle, or a Maia in the form of an Eagle. A subject for an entirely separate discussion, I'm sure.

Oh, one last thing about the Eagles, from Letter 210 (a lovely discourse on how NOT to adapt LotR as a film):

The Eagles are a dangerous 'machine.' I have used them sparingly, and that is the absolute limit of their credibility or usefulness

Deus ex machina, indeed.