STEALTH bombers, giant aircraft carriers and nuclear submarines are the modern symbols of military might, but they are of limited use in today's “asymmetric” conflicts. The old certainties of the cold war have given way to messy urban-guerrilla operations in Iraq, Somalia and Liberia, search-and-destroy missions in Afghanistan and the Sudan, and peacekeeping operations in many parts of the world. This has shifted the emphasis away from expensive weapons systems and back towards individual soldiers. As a result, programmes to develop new “solder-centric” technologies have been launched in America, Britain, Germany, Italy and other countries.

“Right now, we aren't losing any submarines or aircraft carriers,” says Edwin Thomas, the head of the Department of Materials Science and Engineering at the Massachusetts Institute of Technology's Institute for Soldier Nanotechnologies. “So spending money on protecting soldiers is really the right thing to be doing.”

Modern soldiers are hardly short of technological gizmos. Over the years they have been weighed down with all kinds of gadgets, in addition to their usual weapons, equipment and provisions. A survey of American soldiers—the first conducted in 40 years—found that an infantryman typically carries around 120 pounds, or 55kg, on his back. “If I were to put 120 pounds of kit on you with a weapons system, and then tell you, ‘Okay, now I am going to shoot at you, and you're going to shoot these targets,' you would understand how truly difficult it is not only to accomplish your mission, but to just stay alive,” says Jean-Louis “Dutch” DeGay of the American army's Future Force Warrior (FFW) programme, a $250m effort to devise military technologies for deployment starting in 2010.

Individually, each radio, satellite-positioning unit or night-vision system works well; the problem is that these separate devices do not work smoothly together. So the aim of the FFW programme, and of similar efforts such as Britain's Future Infantry Soldier Technology project, Germany's Projekthaus System Soldat and Italy's Soldato Futuro initiative is to integrate all of these technologies to create a seamless partnership with the soldier. The result, if it works, will be to transform each soldier into a kind of part-human, part-machine cyborg—“an F-16 on legs”, as Mr DeGay puts it. The best way to think of the soldier of the future, he says, is “as an integrated, mobile weapons system, like a Bradley fighting vehicle or an Abrams tank.”

This means rethinking every aspect of a soldier's equipment. “We have stripped the soldier down to the skin,” says Mr DeGay. In future, that skin will be clothed in a uniform made up of three layers. Closest to the skin will be a layer of clothing, embedded with sensors that can detect whether the wearer is injured, dehydrated, exhausted or even asleep. In the event of injury, vital signs can be measured to assess the soldier's medical condition, and this information, plus the soldier's exact location, can be transmitted to a medical team, so that it knows what to expect and can act quickly when it arrives.

The second layer consists of “electro-textiles” that provide power and data connections to these sensors, and to the various other devices being carried by the soldier. Radio antennae can also be incorporated into this layer. Finally, the third and topmost layer consists of a new kind of armour. Existing armour stops bullets, says Mr DeGay, but it is heavy, and its snug fit means that the impact of a bullet can still cause broken bones or internal injuries. The new armour, which will be battle-tested this summer, is based upon flexible Kevlar plates positioned a few centimetres above the skin. This means the plates are better able to absorb and distribute the impact of an incoming round—and also makes the uniform cooler to wear.

Although this new uniform integrates the various devices carried by an individual soldier, the next step is to connect the soldiers themselves, so that they can exchange information and function smoothly as a unit. That, says Mr DeGay, requires turning every soldier into a living, breathing, fighting internet node, linked to every other soldier and vehicle at all times. “We affectionately call this the Borg effect—everyone is part of the collective,” he says, referring to the race of cyborgs from “Star Trek”.

“Individually, each radio or night-vision system works well. But these separate devices do not work smoothly together.”

A centrepiece of this effort is a helmet with a Borg-like eyepiece. It displays an image that appears to hover in space in the wearer's field of vision, like a 19-inch television at arm's length. This will make it possible to deliver battlefield information to soldiers from other sources, in effect extending their senses. If a squad is moving through the desert, for example, a drone aircraft might fly ahead of the soldiers and send back pictures of enemy troops lying in wait. Similarly, the display can act as a digital map and compass, can show the positions of other soldiers nearby, and might even show real-time video from elsewhere on the battlefield—all of which adds up to “expanded situational awareness”, as it is known. “We always talk about firepower being the true power, but knowledge is the true power,” says Mr DeGay.

And these technologies are just the start. The Future Warrior Concept, a part of the FFW programme that is intended to imagine the military technologies of 2025, envisages a helmet, similar to a motorcycle helmet, with a 180-degree display, armour with built-in heating and cooling systems, and an array of sensors to extend the soldier's senses still further. All of this is wrapped up in a futuristic black uniform.

While the FFW programme is the flagship of America's efforts to revamp tomorrow's soldier, it is not the only such programme. The Defence Advanced Research Projects Agency, an American military research organisation, is funding the development of exoskeletons, for example, that use external hydraulics and pneumatic systems to endow soldiers with superhuman strength—though such systems are still far too bulky and power-hungry for battlefield use. Another approach, being pursued at the Massachusetts Institute of Technology, is to use nanotechnology. Dr Thomas's five-year, $50m project is developing smart fabrics for use in “battlesuits”—second skins that can make soldiers stronger and less vulnerable. One smart fabric generates energy from sunlight; another contracts like an artificial muscle when a voltage is applied.

Other advanced technologies are under development at SRI International, an independent research institute based in Menlo Park, California. These include a system to locate snipers, which relies on sound sensors wired into the clothing of troops in the vicinity. These pick up the sound of the sniper's weapon being fired, and acoustic analysis then determines the sniper's position, says Scott Seaton of SRI's Engineering and Systems Division. Also under development is a system that uses SRI's PenRad penetrating-radar technology to allow soldiers to see inside a building before entering it.

Technological overkill?

But will soldiers be able to handle all this technology and the torrent of data it will provide—or will it add to the chaos of war? The aim of “human-systems engineering”, says Mr DeGay, is not to bury troops in data, but to act as amplifiers for the mind, body and senses. “We're trying to avoid paralysis by analysis,” says Mr Seaton. “When the shooting starts, you don't want to be looking at your computer. You need to being paying attention to what is going on around you.”

Yet when it comes to making soldiers more machine-like, says Colonel Kip Nygren, head of the Department of Civil and Mechanical Engineering at the Military Academy at West Point, there ought to be more discussion about where to draw the line. “We have become our technology,” he says. “It's something we need to talk about—we are moving really rapidly ahead technologically, but politically we need to have these discussions.”

If the technology really does work as advertised, however, might it eventually do away with the need for human soldiers altogether—and allow them to be replaced by robots? The first steps have already been taken: drone aircraft have already been used to fire missiles. But for the foreseeable future, people will still do the killing on the ground. “Humans have got to be in the loop,” says Dr Thomas. “It is probably going to be necessary for the next 20 years, maybe 100.” The technology of warfare may be more elaborate than ever, but the soldier of the future will still be a man, not a machine.