Those Crazy Ainur...

[doug*platypus]

I love the name of this thread, Bom, good work. I can call you Bom, can't I? No? Oh, sorry.

Give a man a fish and he'll eat for a day.
Teach him how to fish and he'll eat forever.

Gandalf. Fishing instructor supreme. Makes Bilbo a hero, makes Frodo a hero, makes Sam a hero, you see where I'm going...

Also, I think the Third Age conflict was considerably wider than the First Age one. If the Valar/Maiar waged war, they would have risked scaring the wits out of the Haradrim and the Easterlings (of course I'm working on the very fuzzy assumption that the war would have been waged at the time of the War of the Ring). Many would have been destroyed, and Iluvatar would not have been a happy camper, possibly grounding the Valar with loss of all TV privileges. Maybe the Istari were sent to find a possible peaceful solution? Not very likely considering the bloodiness of all the tales, but is it possible?