Given that the United States military spends a large amount of its resources fighting to secure regions of the world that are most important as a source of crude oil, it would certainly make tactical sense to reduce its dependence on those fuels. Some small scale tests of biofuels in military vehicles have occurred in recent years.
The U.S. Navy has now decided to collaborate with the U.S. Department of Agriculture to make a large-scale move to biofuels. Energy consumption will become a standard component of all purchasing decisions over the next several years. By 2012, the navy wants to have a "green strike group" of nuclear and biofuel vessels sailing with a larger fleet by 2016 that also includes biofuel-powered aircraft. By the end of the decade, the navy wants half of all its energy needs to come from alternative fuels.
Since a large part of the fleet is based out of Hawai'i, the military will be working with sugarcane growers there to produce the advanced biofuels.
[Source: U.S. Department of Energy]