I've had the pieces of this in my head for a long time, but fragmented. Only now do I realise the effectiveness and simplicity of it all.
Growth needs resources to feed on - cheap labour to exploit, and steady demand in one way or another. What's the quickest way to create both a cheap source of labour, and a large demand for essentials?
Why, war, of course!
Creating a psychological demand for luxuries requires work, which is why, perhaps, it's only essential for places where creating a war is (currently) out of the question. Everywhere else, destruction breeds desire.