Expansionism

Vietnam is getting seriously frightened by the expansionism of China.

I think that because the world demographics foretell a shifting to a much older population, it may help foster a global trend towards sustainability instead of expansionism. Such an outlook may affect phenomena like space colonization. If the population gets too old, would people still be motivated to colonize space?

Are global population projections correct that assume a greater elderly proportion and an eventual dip? Will society shift its general philosophy from expansionism to sustainability?

European colonialism exported its domestic, counter-revolutionary Inquisition around the world, starting with Portuguese expansionism around 1500 C.E.