Perhaps Thucydides’ most famous quote is from the Melian Dialogue. The Athenians tell the Melians, “The strong do what they can, the weak suffer what they must.” For thousands of years, small states have faced the Melians’ choice. Today, Eastern European nations face much the same problem – a large neighbor that thinks it should dictate life to them.

Fortunately, the convergence of commercially available technology is changing this fact. It is creating small, smart, and cheap weapons that, combined with some existing arms, can provide small states with sufficient combat power to deter large neighbors.

To start the discussion, we must consider two key factors: European willingness to fight and European geography. A 2015 Carnegie Europe poll found that only 48 percent of Europeans believed their nations should defend an ally. Phrasing the question somewhat differently, a WIN/Gallup poll found that only 25 percent of Europeans would be personally willing to fight for their own countries. And even if NATO decides to fight, its low military readiness and poor transportation networks to Eastern Europe mean significant reinforcements can’t arrive in time.

Unfortunately, geography means Russia can overrun the Baltic States and parts of Poland within days. At that point, the front-line states have to count on NATO nations being willing to fight to retake their territory. And Russia has already suggested it might “escalate to de-escalate” — use tactical nuclear weapons — to prevent NATO forces from ejecting Russia from conquered territory.

Thus the fundamental problem for front-line states is to deter Russia or, if Russia decides to invade, to defend long enough for NATO forces to arrive. To do so, they need to develop new deterrence capabilities based on 21st-century concepts rather than counting on the 20th-century air and ground forces they currently own.

Fortunately, rapid advances in task-specific artificial intelligence and 3D printing mean that small drones are now capable of autonomous operation. In 2014, a University of Virginia professor produced a hand-launched, 3D-printed, autonomous drone with a range of 30 miles. Its guidance system was a common cell phone. It could also carry a light payload, such as a 3-ounce explosively formed projectile warhead which can penetrate one-half inch of steel. By adding the warhead to the drone and using the cell phone for targeting, it could, say, wreak havoc on the fuel and ammunition vehicles that support Russian maneuver forces as well as destroy multiple rocket launchers and towed artillery pieces.

Advanced manufacturing and robotics allow such drones to be mass-produced. While it took the professor 28 hours to print his drone, a half-decade’s technological advancement has brought us Carbon 3D printers that can produce them 100 times faster. UPS is building a 1,000-printer plant in Tennessee. Thus production of 100,000 drones a day from a single plant is possible. Once printed, the drones could be installed in standard containers for both shipping and employment.

These might resemble China’s truck-mounted system for launching up to 18 JWS01 drones. The JWS01 is based on Israel’s Harpy, an autonomous hunter with a range of 600 miles and a payload of 55 pounds. Commercial firms have built autonomous drones with ranges of up to 2,000 miles and are also rapidly developing non-GPS reliant navigation, strong visual- and IR-identification software, and electronics hardened against bursts of radiation energy. These advances mean a family of autonomous active hunters can be produced for reasonable costs.

Further, the technology that is creating cheap, autonomous drones can also reduce the price of cruise missiles. By putting them in standard shipping containers, we can create weapons that are easily transportable, easily hidden, powerful (1,000-pound warheads), and long-range (1,500 miles). And they will not be tied to easily targetable airfields.

Then add the old technologies of obstacle engineering, mines, and improvised explosive devices. If the IEDs use ammonium nitrate fertilizer as their base explosive, they can be created easily from the thousands of tons of fertilizer available in the front-line states. And they can be big; a 20-foot shipping container can hold 50,000 pounds of ammonium nitrate.

If front-line states combine these systems and then focus their reserves on their rapid deployment and employment, they can create dense, deadly obstacles for Russian forces. Reservists would be trained to rapidly place IEDs in advantageous locations, then remotely detonate them as Russian forces approach.

At the same time, they might launch thousands of drones to autonomously hunt wheeled vehicles on the Russian side of the border to destroy Russian logistics and fire support assets.

NATO nations farther back could employ long-range cruise missiles and drones without having to move them forward through the logistics networks. Thus they could immediately support the front line states with heavy reinforcing fires.

Using this concept, NATO can build an affordable defense that mobilizes in hours not days or months. It will deploy tens of thousands of active hunters backed by dense webs of IEDs and mines. By using commercial containers, NATO can make it almost impossible for Russia to conduct pre-emptive strikes simply because they are too many containers to target. And these are missions appropriate for reserve forces that lack the time and resources to train to fight Russian armored forces.

Finally, NATO should hold well-publicized demonstrations each year of mass drone strikes, cruise missile attacks, and the detonation of one 50,000-pound IED. To work, the approach requires Russia to be aware of the consequences of attack. For while any bear can eat a porcupine, it won’t.