Too elaborate of a sentence to my understanding

[HaraKiriBlade]

This is taken from an introduction page of the famous novel, Catch-22, by Joseph Heller.

Catch-22 was the American book that - perhaps more than any other of its time - voiced the anxious, absurdist, outragious reaction of a generation to a dark conflict that had taken American soldiers and airmen to Europe, and concluded not just in the defeat of totalitarianism, but in a victor on behalf of the world of our glossy, often alienating, post-modern affluence.

There's not a single word I don't know, and I also get the grammatical structure. But somehow I lose my train of thought along where it says "in a victory on behalf of the world of...".

Why a victory "on behalf" of the world of our post-modern affluence?
Why not a victory of the world of our post-modern affluence?

[Tdol]

I have to say, why not indeed.

[HaraKiriBlade]

Do you happen to know why 'on behalf of' is added in the sentence?