This is going to be debated heavily into the future.
The real problem with the "It produces about 1.1 units of energy when it burns for every 1 unit of energy it takes to make the stuff.", is where do you start and end the accounting? Do you include the portion of the defense budget dedicated to maintaining a supply? Do you include the subsidies? They count the fuel used to raise the crops as part of the formula, but if they use Bio diesel or Ethanol to produce it, where do you draw that line.
What about the security provided by a home grown energy supply?
If we had a secure domestic energy supply, and the most efficient military capable of shutting off oil distribution anywhere, who would be their Daddy then?