There's been a considerable push for the Armed Forces to use alternative fuels, and while part of the reason has been a focus on being environmentally-friendly, there could be a bigger reason for the campaign. A growing number of military officials believe using alternative fuels is crucial to national security, Military Times reports.

The threat comes from the growing instability in many oil-rich regions of the globe. In fact, a number of officials say they have seen troops get injured transporting oil, and while they are not calling for a complete overhaul, many officials believe there need to be more options available.

"When I say flexibility, I mean choices – choices that allow us to have alternative fuels, choices that allow us to make our combat capabilities our edge," former Air Force Lt. Gen. Norm Seip told a panel recently, according to the publication.

Not only does it threaten national security, but relying purely on fossil fuel is especially costly. The Armed Forces burns about 325,000 barrels of oil each day. In 2010, the military spent about $15 billion on fuel, according to CNN.