It's not just about having the power...

[alatar]

Originally Posted by Legate of Amon Lanc

Indeed. But it's interesting to think what might have happened had Gandalf remained locked up inside Orthanc. Had Sauron launched his attack against the West and crossed the Anduin, he would have ultimately come to Isengard. Maybe Gandalf might have found a way to persuade Saruman... I am entertaining myself by this idea: with the Enemy on move, crossing Anduin and getting closer and closer to Isengard, Gandalf persuades Saruman to join forces with him, make the last effort and make the last stand against Sauron. Oh...

Assume for the moment that the story plays out pretty much like it does, except that Gandalf stays atop Orthanc and Elrond sends Glorfindel in place of Gandalf (and Glorfindel knows how to take out a Balrog!). Anyway, Saruman would then be crazy to leave Orthanc to see if his Uruks were bringing hobbits to him. With Gandalf there, Saruman is then stuck in Orthanc. Could Saruman empty his holes to attack Helm's Deep when Gandalf is still there? What if Gandalf and Saruman slug it out, and Gandalf emerges victorious, as the White, smack-dab within Orthanc?

Regarding the Valar and Melkor: Maybe even the good Valar (Manwe et al) began to love the works of their hands more than obeying the will/mind/theme of Eru. Everyone downs Feanor for not yielding the Silmarils to heal the trees, but nobody (but me, but I don't like anybody ) faults the Valar for not smashing Arda if need be to remove the stain of Melkor.

Like I've said previously, Arda is as much a test for the Valar as it is for our kind.