Oil as energy
He or she with the most energy resources Shall win.
For example , in StarCraft,  when it comes down to it… Whoever has the most command centers, whoever harvest the most minerals and vesting gas is the winner! Typically the losing side runs out of minerals, natural resources etc.
A big strategy is simple; star out the other side, destroy their command centers, their drones, SUVs which mine minerals and vespean gas.
we need more vespeane gas! 
The next century won’t be physical warfare, it won’t be cyber warfare. And what is the digital energy we could harness in the next generation of cyber warfare? Bitcoin.