WW3 does not seem like such a far fetched scenario to me.
lets just say you are a raging superpower dependent on other peoples resources. You just need to set up a military hegemony ensuring that all resource trades happen with your unbacked fiat paper currency, lets call it the petrodollar.
If a country were to refuse to trade in your reserve currency, which is worthless because you have been debasing it to pay for runaway government spending, then we bomb them. We bomb and torture as many as possible, over a million in more then two decades. Hopefully maintaining control of the resources after we bomb them, despite many of them still shooting at us with the guns we should have taken away from them first.(for their own safety, no need for guns with the infallible US government around.)
Pretty soon things get crazy and crazy countries start trading resources using gold bullion instead of the petrodollar, these countries are growing and relatively financially sound compared to the US and Europe. Lets say Iran, China, India, Russia, and Brazil. Well if this is happening and it invalidates our hegemony over everyone we are going to need to go to war with them or our system will fail. it will start with the first act of war, starving their people, sanctions. These starving people will turn to their stronger leaders who will radicalize them against a common negative element. Seems like the world is ripe for conflict not just at home, especially after the depression really hits people, but all around the world.
Here are some pictures of Iran and Iranian people:
http://imgur.com/a/OrkDh#0
They seem to look a lot like us, do they need guns?
“Setting a good example is a far better way to spread ideals than through force of arms.”
-Ron Paul