I find this topic fascinating. I wonder if men and elves, like ourselves sometimes misunderstand the help that Deity gives to us. I personally believe that God does intervene from time to time in our world, but it is most often through others. To me, Tolkien does the same with his characters. Aid comes in the form of mortal or elvish (or whatever) aid, thus indirectly from Iluvatar.

I think it unfair to call the Valar detached. They recognized their limitations and that they did not understand all the melodies of Ainulindale. But inteference in the lives of those of Middle Earth (men especially) was dangerous because they did not understand Iluvatar's desings in all things. Fearful that they would interefere with those designs, the Valar often withheld any action against the forces of darkness. We must remember that the Valar did not participate in the Third Stage of Ainulindale which is when the creation and destiny of the children was worked out. Therefore they had to be extremely careful about what they did.

Still, they aided from time to time, especially with the sending of the Wizards into Middle Earth. This act sent beings of great power to aid the Children, but still required men, elves and dwarves to work out their own destiny with the guidance and aid of the Istari.