Note: We’re revisiting some of our most popular material from the past 10 months for our newer readers; this was originally posted January 6, 2014. Enjoy!

By Thomas E. Ricks

Want a better U.S. military? Make it a smaller one. The bigger today’s military, the more time it has to spend taking care of itself, maintaining and replicating itself as it is, instead of changing with the times. And changing is what the U.S. military begins to do as it recovers from the two wars of the last decade.

For example, the U.S. Navy recently launched the USS Gerald R. Ford, an aircraft carrier with a price tag of perhaps $13.5 billion. It has some modern aspects, such as a smaller crew, a better radar, and a different means of launching aircraft, but it basically looks like the aircraft carriers the United States has been building for the last half century. And that means it has a huge “radar signature,” making it highly visible. In an era of global satellite imagery and long-range precision missiles (neither of which existed when the Ford’s first rancestors were built), that could be very dangerous. As Navy Capt. Henry Hendrix, a naval historian and aviator, wrote earlier this year, today’s carrier is, like the massive battleships that preceded it, “big, expensive, vulnerable – and surprisingly irrelevant to the conflicts of the time.” What use is a carrier if the missiles that can hit it have a range twice as long as the range of the carrier’s aircraft? It is like putting a short-armed boxer in the ring with one who has a far longer reach.

Indeed, the U.S. Navy, if it persists in its current acquisition course, runs the risk of being like the Royal Navy that entered World War II. Like ours today, the British navy of that time was the world’s biggest. It could throw more firepower than any other sea service in the world. Yet it would prove largely irrelevant to World War II, because its leaders largely had neglected the growing significance of submarines and aircraft carriers, not grasping that both had forever changed the nature of maritime warfare. They further misconceived the role of the carrier and thought of it as a scout ship, providing far-seeing eyes for battleships, when it fact its aircraft had replaced those vessels as the striking arm of the fleet.

Yes, the Royal Navy won the Battle of Atlantic–but in part because the United States gave it destroyers and other escort ships the admirals had neglected, as well as some of the long-range land-based aircraft that were crucial. (One-third of U boats sunk were sent to the bottom by aircraft, and another third knocked out of action by combined air and surface ship action.)

So the issue is, I think, not how to have the most powerful military today, but rather the most relevant military at the point of necessity–a point that we cannot know. To have that, we need a military not is not necessarily universally “ready for combat” at any given moment, but the most able to adapt to the events of tomorrow.

The wrong way to prepare is to try to anticipate what the next war will be and then building a military—on land, sea and air—that fits that bill. The problem with this approach is that the guesses about the future will almost certainly be wrong. In 2000, no one thought we would invade Afghanistan the following year. In 1953, Vietnam was a far-away country of which we knew little. In 1949, Korea was thought likely to be beyond our defense perimeter. And so on.

Thus the best form of preparedness is not “readiness” but “adaptiveness.” And the way forward is not to try to guess, to be less wrong than others, but rather to develop a military that is most able to adapt. It should be small and nimble. Its officers should be educated as well as trained, because one trains for the known, but educates for the unknown—that is, prepares officers to think critically as they go into chaotic, difficult and new situations.

As Eugenia Kiesling, a professor of history at West Point, has observed, in the period between the world wars, “Smaller forces brought fewer logistical constraints and more rapid adaptation to changes in technology.” That observation is an argument not for a big jack-of-all-trades military, but rather one that is smaller and optimized through its spending to be nimble.

This is not just to beat up on the Navy. The same issue faces all our armed forces. By and large, we still have an industrial age military—but one that increasingly exists in an information age world. With some exceptions, it is still more about producing mass strength than about achieving precision. Land forces especially need to think less about relying on big bases and more about being able to survive in an era of persistent global surveillance—the all-seeing eyes that are in space, in the digital world, and even undersea. For example, what will happen when the technological advances of the last decade, such an armed drones controlled from the far side of the planet, are turned against us? A drone is little more than a flying IED. What if terrorists find ways to send them to home addresses in the Washington suburbs they found on the internet?

Imagine a world in a few decades in which Google (having acquired Palantir) is the world’s largest defense contractor. Do we then want generals who think more like George Patton or more like Steve Jobs—or, ideally, both? How do we get them? These are the sorts of questions the Pentagon should begin addressing. If it does not, we should find leaders—both civilian and in uniform—who will.

*Readers Note: This article is being republished with the expressed permission of the author – it first ran in The Washington Post.  More of his writing and opinions can be found at his blog, The Best Defense.

Thomas E. Ricks is an advisor on national security at the New America Foundation, where he is a participant in its “Future of War” project. He is the author of five books about the U.S. military, most recently The Generals: American Military Command from World War II to Today.