[mpax]

It’s due to return on energy investment going up due to new productive technologies, aka “capital”. “Capitalism” is an orthogonal issue. To put it in Marxian terms, you can have a socialist community with a capitalist mode of production.

The way new capital reaches the third world can be attributed to globalization of market circuits, for instance, China is currently investing into Africa much like the first world did to China in the past.

Of course, if you define the terminology differently, say you’re an Austrian Economist, the above explanation might appear unintelligable.