Quite interesting work. My main questions are: What is the West? Which countries? and What do decline and death mean, and what don't they mean?

These, I think, should be established as early as possible, and the ideas of Spengler and Toynbee presented afterwards, with points of similarity and difference with your own definitions highlighted.

Some minor points:

- Section 1.2 begins by discussing a crisis in creativity and the changing relationship between the elites and the masses. But then it switches to a list of "challenges" including aging and growing sovereign debt. This is rather jarring and needs to be reorganized.

- It's very surprising to read that Greek philosophers switched focus from political philosophy to individual virtue once the Macedonians and Romans invaded. All of Plato's dialogues that I've read are about individual virtue. Even the Republic is only fifty percent politics and the rest is about the soul. Aristotle too is very concerned with what the personal virtues are and how they can be cultivated.