Saving the environment has never been so deliciously lethal. Or at least that's the way things may be going in the future, if some current trends hold.

It sometimes comes as a bit of a shock to people, but the US military does actually pay some attention to environmental issues. After all, the military has to conduct missions in some environment or another. And many of the things that green energy promotes, like reducing dependence on foreign oil, do get at least a small research and development push from the DoD. The Navy has its "Great Green Fleet" initiative, the Air Force plugs along with its efforts to switch to biofuels for jets. And the R&D labs supporting various types of ground pounders have been taking a crack at greening up, too.

Lest anyone get their hopes up too much, however, the point of a military is more aligned with breaking things and killing people, rather than saving the environment. This is one of the many things that sets it apart from the Environmental Protection Agency. Yet once in a while these things (saving the environment while blowing things up in that environment) come together in fun and exciting ways.

This year's annual meeting of the Association of the United States Army ended on Wednesday. Conceived as a professional development event, it's part trade show, part symposium, and part networking event. As part of the trade show, defense companies show off some new concepts and ideas. They're often more than just the military version of concept cars at an auto show — there are mock-ups and technology demonstrators to help spark chatter between people all up and down the procurement food chain.

One lovely idea was showcased this year by BAE Systems. BAE Systems is responsible for the M2/M3 Bradley, the army's current infantry fighting vehicle. It's a great big armored, tracked vehicle, topped off with a medium-caliber 25mm cannon and anti-tank missile launcher. The current Bradleys are getting a bit long in the tooth and the army has been faffing about with some replacement concepts, most notably the recently terminated Ground Combat Vehicle (GCV) program.

BAE has also been experimenting with putting hybrid electric motors in armored vehicles. This is exciting news to some folks for obvious reasons like reducing greenhouse emissions. While some of the other advantages, like increased range, are pretty self-evident, using hybrid motors has a critical impact on other less-discussed things — like logistics.

A main battle tank, like the US M1 Abrams gets something like 0.6 mpg. Yep, it burns about 1.6 gallons of fuel to move the 70-ton tank a mile. No matter how you slice it, that's a lot of fuel. And every gallon requires some trucks, drivers, and fuel to get it to the tank. All that transportation requires fuel that requires even more transportation and so on. In the very worst case scenarios (delivering fuel long distances via helicopter to remote locations, etc.) fuel can cost hundreds of dollars per gallon.

Beyond that, the DoD is the world's largest single consumer of fuel. This means that the military is going to be sensitive to price shocks and disruptions in supply. At a strategic level, reducing reliance on fuel is a big payoff.

But all this is quite… well, dull. If you're going to spend several hundred billion dollars per year on the world's most advanced military-industrial complex, is it so horrible to ask for something a bit more entertaining?

This is where the other part of the BAE technology demonstrator vehicle comes in. The weapons. One benefit of hybrid electric engines is that it means the vehicle has a lot more electrical power to work with. And electrical power means one important thing: l__asers.

The turret atop the test vehicle has a traditional 30mm cannon in the mount, plus a directed energy weapon. The directed energy weapon is still a prototype and, like most laser weapons, it could be destined to stay like that for a while. It won't be able to do anything too outrageous, like blow up a tank, but these systems provide a good counter-drone weapon, which is something that ground forces may find increasingly relevant in future. The proliferation of cheap, tactical drones is something planners are starting to reconcile themselves to: lasers may be a good counter-drone tool.

Currently, the future for armored fighting vehicles in the US is pretty confused, but paring Earth-friendly environmentalism with cutting-edge lethality may prove a winning combination both militarily and politically. In this budget environment, political considerations are paramount — money is hard to come by and it takes some mighty effective persuasion to scratch up enough to start up a major new program.

If you want to save the environment but aren't keen on shelling out for new weapons (or vice versa), this kind of system might be a metaphorical "spoonful of sugar to help the medicine go down." But if you're very demanding and not only want to protect the Earth but blow up things while you're doing it, hybrid electric laser tanks could let you have your cake and eat it too.