[akhtene]

After reading all the posts here I can only agree that Eru could not deprive the new world and it's inhabitants of free choice by destroying Melkor and setting the ONLY way of existance.

What I strongly believe in, is that Eru would have grieved a lot, having to destroy one of his creations, 'an offspring of his thought'. He probably relied on the 14 good powers to re-educate their stray brother or at least to diminish his influence. It's not Eru's fault that absolute good tends to be quite passive (when it takes some actions it stops being ABSOLUTE good). Its evil that is always scheming and plotting and looking for followers. So if that was Eru's plan (I mean the Valar's influence and Melcor's redemption) it definitely failed.