[the phantom]

The release was according to the promise of Manwë. If Manwë had broken this promise for his own purposes...

Denying Melkor's release after promising it would indeed be wrong. They should never have given Melkor any sort of promise of getting out at all.

the doom of the Noldor, the curse, which Mandos set, worked great woe

Indeed. I sometimes wonder if the feat that Feanor was attempting (overthrowing Morgoth) was possible but could not happen because the Valar doomed it. When the Union of Maedhros attacked Angband remember how close they were to winning?

From the Sil-

...they burst through the Gate and slew the guards upon the very stairs of Angband, and Morgoth trembled upon his deep throne...

...Morgoth loosed his last strength, and Angband was emptied...

Yet neither by wolf, nor by Balrog, nor by Dragon, would Morgoth had achieved his end, but for the treachery of Men.

As you can see, Morgoth was scared, he used up every last fighter he had, and all his guys weren't enough without some of the Men who joined him. And just think- the good guys had almost zero help from Nargothrond and Doriath, two major forces.

We also know that Morgoth was accessible since Beren and Luthien managed to get into his throne room. If the good guys kill all the baddies on the field of battle and Angband was emptied, who's left to defend Morgoth?

Maybe he had a Balrog bodyguard or two? Doesn't really matter since we know elves can kill Balrogs.

Yeah sure, the messenger told Feanor "Vala he is, thou saist. Then thou hast sworn in vain, for none of the Valar canst thou overcome now or ever within the halls of Ea, not though Eru whom thou namest had made thee thrice greater than thou art."

I've always thought that was questionable (as Feanor did). After that time Elves certainly overcame a few Maia, and Maia are of the same race as the Valar. Why should it be impossible to overcome a Vala then? With help from the other two Elvish realms they beat Morgoth's forces, walk into the throne room, Luthien starts singing him a lullaby, and then they tie him in chains and carry him out on a huge stretcher (Luthien singing the whole time) and stick him on a boat back to Valinor where the Valar stick him in prison.

I think the deed was possible if not for the Valar going and dooming that the deed wasn't possible. It makes me think they didn't want the Noldor to succeed. Oh no, those evil Noldor (sarcasm) had to pay for their crime (which likely wouldn't have happened if not for the bungling of the Valar).

So did they doom their effort because they didn't want them to defeat a Vala because it would hit home the fact that they, the Valar, weren't all that far above the Elves (I remember a quote that said they were supposed to be teachers and leaders of Elves, not their Kings and Queens).

Hoo boy. Can't wait to see responses to this post. What can I say? I'm feeling feisty today.