[Raynor]

Originally Posted by Texadan

I think perhaps the marring of Aman is in the Valar themselves. It seems to me that they reached a perceived perfection and crouched there. When the Children of Ilúvatar awoke did the Valar try to carry blessings and some of that perfection to the eastern continent? No, they called the elves to them and their perfection. And what did they do when the rest of the world became suddenly very imperfect? They built mountains and walled themselves in.

Myths Transformed tells us that the valar attacked at the first right moment - any sooner, their action might have caused total annihilation.

Morgoth... had to be fought, mainly by physical force, and enormous material ruin was a probable consequence of any direct combat with him, victorious or otherwise. This is the chief explanation of the constant reluctance of the Valar to come into open battle against Morgoth...The whole of 'Middle-earth' was Morgoth's Ring... Unless swiftly successful, War against him might well end in reducing all Middle-earth to chaos, possibly even all Arda... the dilemma of the Valar was this: Arda could only be liberated by a physical battle; but a probable result of such a battle was the irretrievable ruin of Arda.
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This appearance of selfish fainéance in the Valar in the mythology as told is ... I think only an 'appearance', and one which we are apt to accept as the truth, since we are all in some degree affected by the shadow and lies of their Enemy, the Calumniator.
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The last intervention with physical force by the Valar, ending in the breaking of Thangorodrim, may then be viewed as not in fact reluctant or even unduly delayed, but timed with precision. The intervention came before the annihilation of the Eldar and the Edain. Morgoth ... had in fact been weakened [by war]: in power and prestige (he had lost and failed to recover one of the Silmarils), and above all in mind. He had become absorbed in 'kingship', and though a tyrant of ogre-size and monstrous power, this was a vast fall even from his former wickedness of hate, and his terrible nihilism.