The US defence/war budget could be paid entirely out of gasoline and diesel taxes:

$962 billion / 186 billion gallons = $5.17 per gallon ($1.37 per L)

which would double the price, but still pretty cheap

If we were to price in all the externalities of fossil fuels into the retail price it would be a lot more expensive. It's still way too cheap.

"Make war and taxes, not energy" - the new "conservative" hippies or something.