To mirror real life energy issues, maybe a new tech should be added to the game. That being Renewable Energy Tech. A tech that reduces the amount of oil that is required for war ops and reduces the expenses of a country's daily operating expenses by the percentage of tech investment in renewable energy.

oilers suck already, no need to make them suck even more.

Also, Military tech already reduces expenses too (of units).

and expenses bonus.

I would just like to point out that in the scenario posited by this game, none of us would be wasting time on that nonsense when there is oil (and coal) to be exploited, and we can get ahead of our voracious neighbours militarily and take said oil and coal from them.

infinite amount of oil exists so why should we use renewable energy? this game is post-WW3 not thousands of years in future.