Fascinating Wired article.  Recommend reading.

In Tomorrow’s Wars, Battles Will Be Fought With a 3-D Printer

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….