If we are talking about states or countries, then size matters, not just the physical size of land, which means more resources, but the size of population. A nation state today is like a corporation and the citizenry are its human resources. Those nation states that know how to develop well their human resources and make them into highest productive manpower using highest technology will be the dominant ones. That is kind of stating the obvious. What is not obvious:
- future competition of countries will no longer be in the physical battlefield, as Mutually Assured Destruction (MAD) by nukes kind of makes obsolete any major confrontation between major powers, instead the main confrontation of the future will be about economics, trade and competition for global resources.
- in this competition, the largest states in terms of population have economies of scale and internal markets that no other countries have
- so to balance this skewed playing field and make it level, one way is to work towards unions of nation states which would have much bigger sizes, closer to the largest states:
http://www.defence.pk/forums/world-...-world-order-road-map-future.html#post2675055
Only small and unstable states will be involved in armed low scale combats, which is more of a security problem than anything else. The US getting involved in nation building in Iraq or Afghanistan was a costly mistake. It should leave nation building to regional players (specially countries that are included in the same union in my above post). All the US/NATO should be concerned with is to take out hostile extremists or Al Qaeda safe haven, whenever they appear on the horizon. It does not need to come and occupy where there is nothing to occupy and build something which is not within its ability. AK47 and IED's are good equalizers, but so are drones from the opposite end. As for keeping a presence and influence in the region, the US can do that by helping the relevant countries form a stable regional union, as I described in the above post, so they can take care of themselves to achieve stability, which will open up a lot of trade route from EU/Russia to South and South East Asia, via Central Asia.