[Amarie of the Vanyar]

Wouldn't the Valar do something about it?
Probably not, they don't seem to care for the fates of Humans a lot

I disagree [img]smilies/frown.gif[/img], the Valar care for men, and do all what they can for them:

These things the Valar did, (...) and resolved now to ilumine Middle-Eart and with light to hinder the deeds of Melkor. For (...) Manwë knew also that the hour of the coming of Men was drawn nigh. And it is sadi that, even as the Valar made war upon Melkor for the sake of the Quendi, so now for that time they forbore for the sake of the Hildor, the Aftercomers, the younger Children of Ilúvatar. For so grievous had been the hurts of Middle-Earth in the war upon Utumno that the Valar feared lest even worse should now befall; whereas the Hildor chould be mortal, and weaker that the Quendi to withstand fear and tumult.
Of the Sun and the Moon and the Hiding of Valinor; The Silmarillion

Moreover, men never understood the intentions of the Valar when they were trying to help them (this misunderstanding is likely to be the result of the lies of Morgoth to men, the first Fall of Men):

and Men have feared the Valar, rather than loved them, and have not understood the purposes of the Powers, being at variance with them, and at strife with the world. Ulmo nonetheless took thought for them, aiding the counsel and will of Manwë; and his messages came often to them by stream and flood. But they have not skill in such matters, and still less had they in those days before they had mingled with the Elves.
Of Men; The Silmarillion