The setting: a checkpoint guarded by the United States military. It could be a border crossing, a base, a protected zone in a city under siege, or something else. You, a lawbreaker, want to get past that checkpoint, 300 meters in the distance. You aim your car at the gate and accelerate to 45 mph.

You are in for quite in an experience. The military is going to stage a full-frontal, high-tech assault on your sensory system…in the hopes of not gunning you down.

The Problem

There are more than 2,900 military checkpoints across the world, presenting obvious targets that different people will engage in different ways. Kamikaze jihadists driving vehicle-borne IEDs have one reason to rush a checkpoint. Refugees fleeing an advancing army have another.

“A few years ago, we were having definite issues that people would be rushing these checkpoints,” David Law, the technology division chief at the Defense Department’s Joint Non-Lethal Weapons Directorate, told a group at an industry briefing in Baltimore last spring.

Gen. Anthony Zinni, then commander of the 1st Marine Expeditionary, established the Pentagon’s nonlethal weapons program in 1996. The program “stimulates and coordinates” non-lethal weapons efforts across the military, according to Kelly Hughes, spokesperson, Joint Non-Lethal Weapons Directorate. But the Services procure their own non-lethal weapons and train personnel on them.

Today, Law estimates, that the military spends between $120 million and $150 million a year on nonlethal technologies — much of it aimed at securing borders and checkpoints.

Here’s why. In 2004, the International Committee of the Red Cross estimated that U.S. military checkpoints, primarily in Iraq, were seeing one violent event every day.

Three years later, Maj. Ben Connable, a Marine Corps foreign-cultures expert, offered a partial explanation. When drivers refused to yield to commands, guards had few options. “We started out just by trying to wave them down, by putting a hand out — ‘Stop!’ — with the palm forward. And this wasn't working at all,” Connable said. “There were several incidents where we had shot up vans full of families trying to flee the fighting. It was an Army foreign-area officer who realized that [gesture] was the Iraqi symbol for ‘Welcome, come forward!’ We were actually motioning people to come forward and then shooting them.”

So the military bought 400 green laser dazzlers, which guards began using to blind drivers who tried to speed past controlled points. Immediately, Law said, the frequency of violent incidents dropped to one per week. Since then, the military has issued more than 16,000 of the lasers. “Now, checkpoint issues, you might see one every couple of months,” he said.

There are plenty of reasons for that, including, of course, the U.S. drawdown in Iraq. But Law says “non-lethals have helped this situation,” and they will surely play a growing role in managing checkpoints in the future.

Scene: Rushing a military checkpoint

When a checkpoint encounter escalates to violence — even when no one dies — the aftermath can snarl a checkpoint for hours, increasing resentment among the local population. When border guards render a car unusable, for example, it can cause a backup and long lines. So the military has asked the Directorate to develop a Notional Escalation of Force: basically, a plan to apply a hierarchy of non-lethal, and in the last resort, lethal effects. Here’s what that looks like.

Back to you, in a car, moving at 45 mph toward a checkpoint 300 meters down the road. The guards spot you; they have precious little time to decide whether to kill you. They’re going to try to slow you down. The first thing you’ll encounter is a series of bright lights and noise. You may hear the clear, amplified voice of one of the guards, coming through a distributed light and sound array.

The Defense Department is currently exploring an 8-speaker, 144-decibel system to achieve this intimidating effect. “Long-range acoustics work pretty well and here’s a case where one plus one equals three. You put both of them together and it is a wonderful and unambiguous warning. There’s nothing really earth-shattering about this piece of hardware,” says Law.

So-called “focused acoustics” systems can send sound in a more-or-less specific direction. “We’ve got an intelligible voice inside that vehicle with the radio and air conditioning on at 600 to 700 meters. That’s better than anything else I’ve ever seen,” said Law.

You ignore all of this and keep going.

300 to 200 Meters

Deafening explosions now erupt all around you. These are non-lethal pyrotechnic grenades, so-called flash-bangs. You have to look away; the guards are aiming their dazzling lasers into your eyes. (Don’t worry. Causing permanent blindness with a laser is against international law.)

You suddenly feel an intense prickly feeling. This is the military’s Active Denial System, or ADT. Unlike microwave guns, the ADT uses 95GHz, or millimeter-wave radiation. The waves reach only a 64th of an inch into skin at a 1.5 nanometer spot. The military describes it as an “intolerable heating sensation.”

It was deployed to Afghanistan but has never been used in combat. But it could be. The military has put it through a full legal and treaty review and it has been found to be “compliant with the international legal obligations of the United States,” according to Hughes. "These reviews have determined there are no legal prohibitions to the development and use of this technology when it is employed properly and in accordance with appropriate tactics, techniques and procedures,” she added.

Let’s assume that the ADT doesn’t fire for some reason, or there’s some hesitation on the part of the border guard to use it, or you’re a genetically engineered supervillain who lacks nervous matter on the surface of your skin. What happens next?

200 Meters to Checkpoint

The military is done trying to persuade you to abandon this unfortunate course of action. At this point, they’re focusing on your vehicle. They might use a radio-frequency stopper to disrupt your car’s electronics — or they might start firing on it directly, at about 100 meters.

Once you get to the checkpoint itself, get ready for a shock. As you cruise over a speed bump, a pair of electric fangs attach themselves to the underside of your car, sending 150,000 volts into your undercarriage, disrupting the engine control unit and stalling your vehicle. This is what’s called a pre-emplaced electric vehicle stopper.

It’s a last line of defense, aside from shooting the driver. It halts a vehicle about as well as a net gun fired at a tire, but — unlike the net — it allows the car to be started up again and driven out of the way.

Your vehicle is temporarily inoperable. Your vision and hearing are returning to normal. The stinging sensation on the surface of your skin has subsided. Physically, you’re fine. but you’re not getting past that checkpoint.

(Photos via Joint Non-Lethal Weapons Directorate)