To me it doesn't look like the powerful have given up power, it seems as concentrated as ever. It is more that the concept of a nation isn't that useful to them under globalization at least not in the same way.

Some of this is due to changes in technology. For example as farming improved with the green revolution shear land area counted for less, and shipping and refrigeration allow longer distance imports.

So rather than land area control you see more localized strategic resource control. Things like mines, oil fields, shipping lanes etc.