A 3-D printed drone is shot down by insurgents near a far-flung base manned by the U.S. military. Within hours, a small lab dropped onto the base by a helicopter days before churns out a replacement – along with plenty of ammunition and reinforced shelters for the troops. A few miles off a nearby coastline, a naval ship-turned-factory harvests resources from the sea and uses on-board printers to make everything from food to replacement organs.

It's a far-out vision for future combat, but at least one naval officer thinks it could happen. According to Lt. Cmdr. Michael Llenza, who sketched out the scenario in the latest Armed Forces Journal, 3-D printing could arguably "upend the way we think about supply chains, sea basing and even maritime strategy." And by we, Llenza doesn't just mean Americans. The Chinese military is already bragging about how they are printing parts for their next-gen aircraft.

Aside from drones – which have already been printed – ammunition could potentially be produced with the machines, as the casings would be "relatively easy," he writes. (The Pentagon would just have to find a way to produce the propellants.) Additive manufacturing also "offers a new way to think about building shelters or other structures on a beachhead or forward operating base." The hope, as the theory goes, is that large-scale investments in 3-D printing could take a lot of strain off the supply lines modern military forces depend on to survive.

None of this amounts to the official position of the Pentagon, but publications like the Armed Forces Journal serve as influential arenas where many theories and ideas from military officers – some which are later incorporated – are first put up for debate. And it's no surprise the potential (and existing) military uses of 3-D printers has been getting a lot of recent ink.

In April, Navy lieutenants Scott Cheney-Peters and Matthew Hipple sketched out a theoretical future Navy in the widely read U.S. Naval Institute journal Proceedings that imagined ships capable of harvesting the oceans for 3-D printing material, and floating factories capable of manufacturing repair parts for a fleet of ships. Even shipyards, the authors wrote, could be effectively converted into giant 3-D printers. Llenza, who is also a Senior Naval Fellow at the non-partisan Atlantic Council, has taken that concept and run with it.

But there are also dangers, he warns. It's not the 3-D gunmakers who are posting videos of their weapons to the internet. Those guns are crude and expensive compared to a homemade zip gun or bomb. "As far as printing guns, I'm not worried about it in its current state," Llenza tells Danger Room. "I'm more worried about knee-jerk legislation and some idiot getting a hold of one. Plans to make zip guns and bomb making recipes have been online forever, so not much is new there." (Though over time, the technology could advance with machines that can work with both metal and plastic simultaneously, or with printable composite materials that can withstand the heat and pressure of repeated use.)

Llenza is worried about larger military-grade material being reproduced by anyone with a 3-D printer. "This has implications not just for corporate intellectual property but national security," he says. That could mean, for instance, military blueprints for a 3-D printed device or weapon being pirated and re-produced on the fly, instead of having to physically steal a machine and reverse-engineer it. Even more radical, Llenza writes that spies could one day use a "hand-held computed tomography scanner" to peer through containers to scan weapons, which "automatically generates the digital blueprints to print it." Or hack 3-D printers as a form of sabotage.

3-D printers are also being incorporated into the armies of America's potentially future foes. China, a rising competitor to the United States, does not have the luxury of a global and (relatively) efficient supply chain for its military, nor does it have a network of bases around the world. China has decided to sidestep the century it took the U.S. to develop its carrier fleet – though China is not nearly at the U.S. Navy's level, and it's another matter entirely when it comes to putting an operational carrier to sea for months. But 3-D printers, Llezna says, could help China move a little faster.

"First off, these are my opinions and not the U.S. Navy's. Now that that's out of the way, absolutely, China is 100 percent all-in on this," Llenza tells Danger Room. "The technology has great potential to shorten logistical supply chains, and is especially beneficial to a state which is developing a deployable navy." That includes titanium parts China is now printing for the J-15 Flying Shark – a carrier-borne fighter currently being developed. The J-15's chief designer told Xinhua News Agency in March that printable components are being used "in major load-bearing parts, including the [J-15's] front landing gear."

The U.S. has yet to certify 3-D printed parts for load-bearing structural aircraft parts. "Frankly, as an aviator, I'd like my parts to be certified before I go flying with them," Llenza says. "But it goes to show, if they're telling the truth, that they've bought in. Also, and again, this is my opinion, but the ability to print titanium and employ these lightweight parts in their aircraft can only help with what I understand to be a history of fabricating underperforming aircraft engines."

In the end, the Pentagon may be better positioned, or at Llenza hopes. The military already uses 3-D printers to manufacture some non-critical components for aircraft, and has deployed prototype 3-D printing labs to Afghanistan. The Obama administration has plunged into 3-D printing technology, pledging $200 million in funds this month for three proposed research institutes that include 3-D printing as a key area. The Pentagon will oversee two of those institutes. So perhaps that 3-D printed military isn't as far off as it might seem.