The thing is - well, actually, there’s two things.
One is that I don’t think they asked Eru for help. I don’t think that’s what the resignation of the Regency of Arda was, right.
That was an admission by all of them that they didn’t know what to do, and everything they could think of to do was Wrong; it was a surrender. And despite what Elendil tends to use as his frame in Akallabêth, it is not at all clear that what Eru did in the intervention was primarily about punishing Númenor.
Because Sauron had managed to pull off the perfect fuckery against his siblings, right. That’s why he “surrendered” to Pharazôn to start with. It’s not like he could just sail to Númenor personally and deal with these fucking assholes who kept screwing with all of his plans. He’d sort of thought that maybe once they stopped being friends and allies with the Quendi they weren’t a problem anymore - Gil-galad wasn’t going to be suddenly pulling a new fucking army out of his asshole to rescue himself, because Númenor wasn’t talking to him anymore.
Except then. Then. Then these fuckers just go into empire building and colonizing on their own! They become a straight up rival! Sure they stop being the Eldarin ace in the hole of “fuck off with this whole empire thing” and shite but they just start being their own conquering empire and are now competing with him directly for control over Middle-earth!
But he can’t just … .SAIL OVER THERE because the Ocean Is Still Bad, right. The Ocean means dealing with Ulmo and Ossë and Uinen and crucially Ulmo is 100% the Vala that just fucking interferes when he thinks he can get away with it and feels like it’s worth it and so sure maybe Manwë’s said “we’re not dealing with Sauron directly because at this point Arda really can’t take any more fuckery of Ainu-fighting-Ainu level anymore”, and maybe even Ulmo agreed when they had their meeting … .
… but if Sauron just like, gets on a boat and tries to go fuck with their special pet island, he is pretty damn sure Ulmo’s going to smack him out of existence and then go “who, me?” when Mandos goes what the fuck, AGAIN????
He did, after all, turn that fucking Lúthien’s fucking granddaughter into a bird and then just expect nobody to do anything about it, right.
But now. Now this pissant little Melianling king is going to take Sauron home with him. Ulmo is not going to do anything that puts one of Melian’s little fuckbabies at risk, any of Lúthien’s extremely irritating little spawn. So this idiot takes Sauron allll the way to Númenor by himself!
Now Sauron can set up the best thing ever, where he gets to both wreck his rival empire (both literally and spiritually) and set up an endless shit-fest for his sibs.
Because like let’s be real: Pharazôn’s fleet was no real threat to Aman. Tol Eressëa is populated by the survivors of the first war with Melkor, and the only nation of Quendi in Aman who didn’t directly fight in the War of Wrath were the Teleri. In terms of pure military force, before you even talk about the Ainur there, Pharazôn’s army is going to hit the shores and immediately start getting burned out by the fact that there’s just too much power there, and then also hit entire armies of really angry Eldar, Noldor and Vanyar who actually know the terrain.
Or, you know, Aulë himself could just open a chasm under them and close it up again.
But that doesn’t matter, because what Sauron’s doing isn’t trying to conquer Aman by sending Pharazôn there. What he’s doing is delightedly using Lúthien’s descendants to force the Valar into the position of having to either use the Quendi to kill the Númenóreans he’s deceived, or do it themselves….
…..and then do it with the next wave.
Because Pharazôn’s fleet isn’t going to succeed, but it is going to get wiped out. And from the point of view of the surviving civilians left behind (carefully shepherded by Sauron himself) that’s going to be the Murder of our People by the Terrible Vengeful Demons of Aman, and he knows enough about humans by now to know that if you raise them believing that, you can build up the next wave of an attempt to attack the gods. It doesn’t matter that the first one failed, you see - it’s that the first one tried it and there was something to fight.
And the next one. And the next one … .
Sauron is setting up an eternal actual war: the Valar are either going to have to break their hands off declaration and come get him directly (and he knows they’re not going to do that because that fight risks breaking all of Arda - all of millions and millions of people who have no part in this yet, even); or they’re going to have to turn the Quendi of Aman into their bloody-handed enforcers (eventually meaning that he has created a world where Eru’s two Children are eternally in direct war, because fuck knows Quendi aren’t above developing fixed hatreds, and do that long enough they will!); or they’re going to have to kill wave after wave after wave of one of Eru’s Children themselves.
It’s fantastic. There’s no win condition here.
He just … isn’t the kind of mind who would expect that what this would lead the Valar to do is to admit that they’ve failed. That they can’t find the option that avoids this. That they don’t know a way out and all three of those choices are horror, we have failed you, father, and are no longer worthy guardians for the creation we shaped; we have failed to stand in your stead.
Which is what I think that resignation is.
The other thing is … . gonna be real with you: Númenor is not the world, and the cost of most of one (1) island’s population to completely remove the possibility of this threat being real again isn’t actually more than the wholesale destruction of a continent, and the death of nearly everything on it (after all, the Valar and their Maiar have more to love in Arda than just the Eruhini and at most, they managed to save more or less most of the Eldar and Edain from the Drowning of Beleriand - not the plants and animals and insects and trees and everything else); the devastation of a tiny spit of land that was home to what was, by that point, a poisonous malignant force for terror, suffering and death among its fellow Atani … .well.
And the thing is what Eru did was more or less akin to what they did, wrecking Beleriand to save the rest of the world, because the actual point of Eru’s intervention was the physical reshaping of Arda without destabilizing and destroying it. For the cost of that one rotten island, Eru rewrote how space, time and reality worked so that it was not possible for Atani to get to Aman. It was no longer possible for the Valar as Regents of Arda to be put into the position of having to choose between destroying Arda or being at active eternal war with one group of Eru’s Children.
Could Eru have done that in a way that did not actually cause that harm? Honestly I don’t think so. The actual text makes it pretty clear that Eru is not actually all-powerful - Eru is framed as far far wiser, more powerful, more, than the Ainur, Eru is framed as the source and font of actual [life], as the Creator; and Eru is framed as being much better at all of this, in the claim that with the Third Theme no matter what fuckery Melkor and his ilk have pulled it will eventually be brought around to a full and good end.
But Eru didn’t shape Arda; Eru put the spark of [life], of its possibility, the power of being alive into it, Eru carved out space in the wide Universe that would be Eä where the blueprints of the music, so to speak, could then be acted on by the Ainur; but there’s nothing actually in the text that claims omnipotence.
Eru is more powerful. Eru has what the Valar did not, which was a way to reshape Arda to remove this threat without simply destroying it, leaving it to pull itself apart. And Eru did so, and honestly given that it cost an entire fucking continent to get into Angband and drag Melkor back out, one (1) little island isn’t … a lot.
Do I think Varda grieved it? Absolutely. Do I think she would have wished that there was a way to do it without even that cost, for the hope that even this little now-poisoned island of people could … figure their shit out and throw off her shitty little sibling’s bullshit? Totally.
It will absolutely be just one more piece of Nienna’s eternal agony of grief for everything their worst sibling has done, since they even started with this creation.
But I don’t think, for what it did and for what it was averting, that it counts anywhere near to the scale of what her restraint seeks to avoid. Númenor died, but in its dying millions of Atani were actually liberated from a really hideous yoke of enslavement; and in the changing of the world, this threat can never happen again; and for that matter in this, Sauron himself is reduced sufficiently that it may be possible to get the fucking fuck rid of him, and then watch and try to guide and wait for the working-through and reweaving of the damage of Melkor’s themes by the Atani - however heartbreaking some of that may be - play through on their scale, a scale that does not threaten to break reality, whatever else it does.
And I don’t think that’s a bad alternative to the moment that they faced otherwise and the knowledge that in that moment there was nothing they could do, no course they could take, that wasn’t setting in motion even more evil spinning itself out forever.
I think in a lot of ways, if anything, Númenor’s destruction was the price for saving Varda from actually having to hit the point, eventually, of “ … .you know what, fine: it isn’t worth preserving this anymore, even after we shoved the fucker into the Void his little disciple has still dragged us to the point that there is nothing left of what we sang of this world except his works, so we’re done.”
MMV. But while our texts are so frequently from a NĂşmenĂłrean point of view (either them, or their descendant cultures who cling very hard to the identity) that NĂşmenor takes on a disproportionate sense of being the centre of the world, when it comes down to it: NĂşmenor was a very little island, and by the time it fell it had already been a cancer on the face of humanity for quite some time. Its not a lot to trade for The World, when you rank it up against a continent, or against having to kill your metaphysical little siblings - the ones you were supposed to be saving - forever, or let their other siblings do it.
