There's a famous line attributed to Mark Twain that is often quoted as a guide to world leaders: "History doesn't repeat itself, but it does rhyme."
With that quote in mind, for the last year I've been taking an informal poll of the joint chiefs who lead the U.S. military, asking them what period in history provides the most apt parallel to today. Every single one answered the early 1990s, when the United States sharply pared its military spending and drew down the size of its armed forces following the collapse of the Soviet Union. These experiences were painful for the military and in many ways haunted the military a decade later in Iraq and Afghanistan, when the force had to be re-expanded and to regain skills and technologies that had atrophied.
With similar worries about force cuts and the utterly unstrategic nature of sequestration budget slashing, the 1990s are an apt parallel. But in looking for rhymes, we too often turn to the songs we know best, not the tune that might better fit.
If there is a natural historical comparison, it is not to the end of the Cold War but the period surrounding World War I. Today, the United States has assumed a role parallel to that of Britain, the previous great power, whose time at the top was just coming to an end.
Seeking the status quo
Like Britain back then, today's United States has global responsibilities but also global burdens. It maintains roughly 800 military bases in 156 countries and accounts for half the world's military spending. And like Britain and its colonial wars, the United States is similarly engaged in conflicts around the planet, though the Boer wars and the Afghanistans of the world remain "small wars": tough, painful and exhausting, but not existential threats.
The United States is now a "status quo power." The term cuts against Americans' popular self-image of themselves as a positive change agent in the world, but the reality is that Americans like the structure of the current geopolitical order as it serves U.S. interests relatively well. After all, the United States sits atop a system it had a large hand in designing -- first in the wake of World War II and then at the end of the Cold War.
Yet, much like the British during the last century, the essential challenge for the United States is trying to hold on as the world changes rapidly around it. The parallels extend from dealing with rising great powers like China, to the loss of competitive edges in economic power and innovation, to the looming loss of the dollar as the world's reserve currency.
Strategists must consider not only the underpinnings of power, but also the will to retain it. Much as then, there is a growing isolationism among the public that the foreign-policy elite had better heed. What we saw play out in the recent Syria vote, where the traditional coalition for use of force lost key wings of both parties, will continue.
A few years back, I surveyed more than 1,100 millennial leaders and found roughly twice the level of resistance to foreign entanglements among the next generation of American leaders as among the current generation of baby boomers -- not unlike how the youth of Britain began to question the unquestionable empire in the 1920s.
Yet, for military planners, what may matter most is the remarkable technological shift lying behind all this change.
It has become vogue for leaders to say that a lesson of the last decade is that "technology doesn't matter in the human-centric wars we fight," as one four-star general put it to me not long ago. But that assumes a definition of technology as the exotic and unworkable. To paraphrase the musician Brian Eno, technology is the name we give to things that we don't yet use every day. When we use it every day, we don't call it technology anymore. Whether it is a stone or a drone, it is technology, a tool that we apply to a task.
The networked battlefield
For the last year, I helped lead a Pentagon project called "NeXTech" to figure out if any "game-changers" loom akin to the crazy new technologies back then of flying machines and underwater boats. It involved everything from interviews with the scientists and investors who will create and pay for the tools of the future, to war games with soldiers and experts from multiple countries, organizations and generations. We even convened a unique gathering of philosophers, lawyers, human rights activists and policy makers to discuss difficult new ethical and legal dilemmas.
The results were startling. Autonomous robotics -- from large drones that now perform the most difficult tasks of human pilots (e.g., the X-47 that recently landed on an aircraft carrier) to tiny systems the size of swarming insects -- are not just moving humans farther from the action in war geographically, but they also are moving them further away chronologically. Key decisions are being made by software developed months or even years beforehand.
Add to that a growing dependence on big data and the "Internet of things." In a world on its way from a few billion devices, each with a human behind them, to one with 75 billion networked together, our computers and the infrastructures they power will increasingly gather data, communicate about it and, most importantly, make decisions -- all without human instruction.
Imagine the way an escalator turns on just before you step on it, or how your car communicates with your house to let the smart thermostat linked to the smart power grid know to change the temperature when you're 10 minutes from home. Now imagine an entire battlefield that operates that way, literally reactive, constantly changing, but also woven with vulnerabilities (we've already seen hacking of these).
As for new weapons, directed energy systems (a.k.a. lasers) are being deployed on Navy ships and for missile defense, marking the first time weapons have employed something other than kinetic force. Meanwhile, 3-D printing allows a computer to make atoms and build them into things -- be it a car part, a gun, even a drone. The ability to prototype rapidly and manufacture on site and on demand represents a massive disruption to the defense economy, one that rivals the impact of early assembly lines.
Finally, "human performance modification" technologies are changing our physical and mental capabilities. Whereas Luke Skywalker had a robotic hand, now we have bionic prosthetics that allow victims of improvised explosive devices to go back into combat even after losing an arm or leg. Consider that 10 percent of the U.S. population now has a pacemaker, drug delivery system or some other medical device embedded inside their bodies.
Humankind has evolved from using fists and stones to guns, bombs and soon lasers and cyberweapons in our wars against one other. But the frail human body remains fundamentally the same. HPM is about changing that fact, encompassing everything from technological hardware implants to chemical effectors that extend stamina, focus, even learning ability.
Will we adapt?
Still, none of this new technology changes the why of war -- our human flaws and mistakes still drive conflict. Nor does it mean that we can ignore the historic lessons of war. War will never be perfect. Indeed, when military aircraft gained widespread adoption in the 1920s, a new breed of thinkers (or false prophets, depending on what military service you are from) like Gen. Billy Mitchell claimed that there would be no more need for old-fashioned ground armies. Yet the need for "boots on the ground" lived on throughout the 20th century -- just as it will live on into the 21st.
Necessary change will inevitably be resisted, sometimes for valid reasons, sometimes for reasons that have nothing to do with battlefield performance. For instance, the British invented the tank yet veered away from fully adapting to the Blitzkrieg concept they arguably birthed, largely because implementing it would have undermined the cherished regimental system at the center of British military culture. This was not just a British phenomenon; as late as 1939, the head of the U.S. Cavalry, Maj. Gen. John Knowles Herr, declared that "not one more horse will I give up for a tank."
One can see eerie parallels today. Discussions in Washington about the F-35 strike fighter -- a plane conceived in the 1990s whose massive budget threatens to strangle a new generation of unmanned systems at birth are as much about identity as anything else.
Likewise, fundamental organizational questions arise in the realm of cyberwar. Much as our forebears in the last century had to figure out battle in the new domain of air, operations in the new cyber-domain were first handled by technical units in the traditional services. Today, many argue that cyberwar should become its own independent service.
No historical parallel is exact -- hence Twain's notion of a rhyme. Unlike the last interwar years, today's security environment is peopled by a wider set of actors who face lower barriers to entry. Eighty-seven countries have drones; 100 possess cybermilitary skills. And that is just to count states. The so-called Syrian Electronic Army, which has bedeviled the websites of everyone from The New York Times to the U.S. Marines, is merely a collective of pro-Assad hackers reportedly led by a 19-year-old. The Lebanese militant group Hezbollah couldn't build or even operate previously dominant battle platforms like a battleship, but it already has used drones.
This swirl of change means that the continued focus in Washington defense circles on traditional approaches to force and resource planning is simply not enough. We cannot afford to think small, consuming ourselves with which budget line item to tweak to mitigate sequestration or how many hundred staff jobs to cut to shave personnel costs. If we ignore the big shifts and fail to ask big questions today, we will set ourselves up for failure in the geopolitics and battlefields of tomorrow.
Winston Churchill may have said it best: "Want of foresight, unwillingness to act when action would be simple and effective, lack of clear thinking, confusion of counsel until the emergency comes, until self-preservation strikes its jarring gong -- these are the features which constitute the endless repetition of history."
P.W. Singer is director of the Center for 21st Century Security and Intelligence at the Brookings Institution. He wrote this for Foreign Policy.