This whole concept of world war 3, I really highly doubt.
We have an on-going war with "ISIS" that alone is costing us so much money. It just means we will settle it through inner deals what the presidents will do for each different country in exchange to avoid blood shed.
One day US cannot continue this expansionist politic without dealing directly with Russia or China, just check what happened with Ucraine and how many other countries can be envolved on war with US's allies (I think we are on red line: only Iran remains).
You're talking about a future global peace, when territories aren't possible to touch without a direct response from Russia or China, using a deal that beneficiates everybody...
I don't know a lot about it, but I think this model of capitalism is completely totalitarist: grow with expasion and eliminate our rivals.
I think wars are actually impossible to avoid.
But a WW3 must mean we failed at all level negogtiations with other nations on something. And it wouldnt be wise to go start another war since we seem to be never paying our trillions of debt we owe.
When US touch direct interests of China with other countries, first thing China will do is claim his part of debt...
