It doesn't do to quarrel with Einstein, and he's no doubt right about World War IV. But implied in Einstein's famous adage is an assumption that right up until the moment we knock ourselves back into the Stone Age, the technologies of warfare will evolve in one direction only: They will become ever more advanced, complex, sophisticated and lethal.
Today, much rhetoric about future wars makes this assumption. We assume that military technological innovation is a one-way ratchet. High tech measures taken by one side will be followed by high-tech countermeasures taken by the other, which will be met with still more advanced counter-countermeasures, and so on, ad infinitum - or at least until some Einsteinian nuclear catastrophe ends the cycle, crashing us back to the age of sticks and stones.
But Einstein's cautionary words overlook one detail: For all our technological sophistication, warfare has never truly moved past sticks and stones - and even today, their bone-breaking power remains surprisingly potent.
It's easy to forget the continued role of sticks and stones. When we think of the history of warfare, we think in terms of perpetually advancing technologies. Certainly, history offers plentiful examples of escalating technological "measure, countermeasure, counter-countermeasure" cycles: As swords and spears grew more lethal, armor became heavier. As armor became heavier, horses were needed to increase speed and maneuverability, and the invention of the stirrup further increased the lethal effectiveness of mounted cavalry.
The development of the long-bow enabled distance warfare and the decimation of mounted troops armed with swords and spears, but then guns and artillery displaced longbows, automatic weapons displaced single-shot weapons, and so on through the atom bomb - for which Einstein's work so ambivalently paved the way.
Or consider electronic warfare. During World War II, for instance, Allied forces developed active sonar to locate submerged German U-Boats, while ship-based high-frequency radio direction finders were produced to intercept radio transmissions sent by surfaced U-Boats. Germany then equipped U-Boats with radar detectors, which led the Allies to deploy newly developed centimetric radar, which German radar detectors could not detect.
In the context of aerial warfare, the evolution of radar systems to detect incoming aircraft led to the use of chaff and the development of radar jammers, which in turn led to new counter-countermeasures intended to making jamming more difficult, such as frequency hopping and radiation homing.
In each of these cases, technological innovation in warfare sparked new technological innovations by adversaries, and today, as in World War II, we're often inclined to assume the inevitability of such technological escalation.
This is the assumption that underlies much current thinking about cyber-threats, as well as the Pentagon's Air-Sea Battle paradigm.
In cyber, the development of Internet-based communications systems is countered by the development of new methods of detecting and disrupting Internet communication; cyberattacks lead to new cyber-defenses, which lead to new and more sophisticated cyberattacks. The Air-Sea Battle paradigm is similarly premised on the assumption that technology marches forward: U.S. air and naval dominance incentivizes near-peer competitors - a.k.a. frenemies, a.k.a. China - to develop anti-access and area denial technologies. And so, the logic goes, we need to invest in anti-anti-access technologies, and technologies to deny area denial.
This, of course, just happens to take money, and lots of it. It also just happens to involve significant investment in the Air Force and Navy, the two services pushed to the sidelines, relatively speaking, during a decade of slow, plodding land war in Iraq and Afghanistan. Fearing displacement themselves, the Army and Marines are pushing their own high-tech visions of their future.
As Lloyd Freeman argued last week, the Marine Corps needs to transform itself, for "in future conflicts, ground troops will only play a secondary role. Land forces will no longer win wars. Computers, missiles, planes, and drones will."
In the future, argues Freeman, the old "every Marine a rifleman" slogan will need to be replaced with a new concept: "every Marine a JTAC" (joint terminal air controller). "Marines will manage and become experts on dozens of different communications platforms," asserts Freeman. "Live video feeds will stream continuously."
Maybe so, maybe not.
Here's what we seem eager to forget: Military technological evolution can go in both directions. In biological evolution, there's no teleology: The simple doesn't inevitably become more complex, and while life forms change and evolve in response both to random mutation and environmental conditions, they don't inevitably "advance." In modern warfare, the same is true. High-tech measures aren't inevitably countered by more high-tech measures. Sometimes, the opposite is true: The most successful countermeasures are low-tech - and historically, this has been demonstrated just as often as has the opposite.
We know this, of course. We just don't like it.
Sticks and Stones in Afghanistan
Consider, most recently, the U.S. experience in Afghanistan. The U.S. brought overwhelming technological superiority to the battlefield - and with it, we also brought new blind spots. The Taliban, a low-budget but by no means low-innovation adversary, quickly developed low-tech responses to our high-tech blind spots.
Unable to prevail in direct combat with U.S. troops, for instance, the Taliban turned to improvised explosive devices made of readily available materials and detonated by cell phone. We countered by developing costly vehicle-based cell-phone jammers, designed to prevent the long-distance detonation of IEDs as our vehicles drove by them. These often had the unintended consequence of disrupting our own communications, and they also led the Taliban to shift to using IEDs with mechanical triggers. We responded by equipping our forces with ground-penetrating radar designed to detect the metallic signature of IED components. The Taliban countered by moving even further in the direction of sticks and stones, constructing pressure-plated IEDs out of foam rubber, plastic, and wood.
We've seen similar Taliban low-tech countermeasures in other areas. We have invested heavily in both encryption technologies and surveillance technologies designed to thwart adversaries' use of encryption, for instance, but since we took it for granted that potential adversaries would have made similar high-tech communications commitments, we allowed our ability to locate simple FM radios to degrade.
Most of the time, Taliban forces don't bother with encryption; they communicate openly over simple handheld walkie-talkies, using multiple mobile FM repeaters to retransmit these weak signals over longer distances. U.S. forces initially lacked the equipment needed to intercept these transmissions, and reportedly had to reply on purchasing cheap "commercially available radio scanners in the Kabul souk" to listen in. The equipment needed to intercept Taliban radio communications became standard, but it has proven far more difficult for us to locate the enemy themselves; we can locate the repeater towers, but not a Taliban soldier on his handheld radio.
Al Qaida, too, is a learning organization. Threatened by U.S. drones, al Qaida is reportedly turning to low-tech countermeasures, encouraging militants to use mud and grass mats to disguise vehicles from overhead surveillance. This tactic won't be successful for long, but it's a good bet that AQ will find new low-tech means to thwart U.S. drones in the coming years.
You get the picture. Sometimes, high-tech measures leads to higher-tech countermeasures - but at other times, high-tech measures lead to lower-tech countermeasures. More ominously, a misplaced confidence in our technological superiority dangerously increases our vulnerability to low-tech countermeasures.
The Moral of the Story
Some will be tempted to dismiss this as an artifact of the ill-fated post-9/11 U.S. ground wars. Though 65,000 U.S. troops remain in Afghanistan, we've already begun to lose interest in that war and its lessons. We should know better.
In the 1970s, we convinced ourselves that there would be no more Vietnams, and turned our backs on whatever wisdom we had gained during that brutal, protracted conflict (wisdom about the nature of asymmetric and guerilla warfare, the strength of nationalism and the perils of occupation). Then, in Iraq and Afghanistan, we painfully relearned many of Vietnam's grim lessons - just in time for the wars to wind down and the public to lose interest.
Now, many leaders in both the military and civilian world seem determined to repeat our post-Vietnam head-in-the-sand routine. We won't have any more Iraqs or Afghanistans, we tell ourselves - we won't invade or occupy states or territories with vast ground forces, and we won't be engaged in messy COIN or stability operations, so we don't need to remember our mistakes - we can just move on! The lessons of Afghanistan will have no applicability to future wars, for these future wars, if any, will be high-tech conflicts with sophisticated state or state-backed adversaries.
Maybe so, maybe not.
Here's the thing: Even if the cyberwarriors and the Air-Sea Battle proponents are right - even if any future wars will be with sophisticated, high tech states - it's a big mistake to imagine that sticks and stones will play no role in future conflicts.
After all, it took the Taliban remarkably little time to realize that high-tech U.S. capabilities could frequently be thwarted by lower-tech countermeasures. Why should we imagine that near-peer states such as China haven't taken notice?
Brooks is a law professor at Georgetown University and a fellow at the New America Foundation. She served as a counselor to the U.S. undersecretary of defense for policy from 2009 to 2011 and previously served as a State Department senior adviser.