Terrorists and insurgents have used digital watches to remotely fire rocket barrages. They’ve used kites to direct artillery fire. They’ve sawed up lampposts to make rockets. They’ve used donkeys to tow makeshift rocket launchers. Improvised explosive devices are, of course, the best known example of building weapons from easily available materials.

In this age of “improvised everything,” the U.S. and its allies could draw a lesson from these enemies by embracing improvisation. To start, our ISR systems are misaligned for the challenges of the post-Cold War era. In fact, our ISR suite is a complete reversal of what is ideally needed. The U.S. cannot passively ride out the wave of IED threats when a tsunami of change is looming.

In the Cold War, the U.S. intelligence community focused on deciphering the capability of an adversary’s weapons. Billions of dollars were spent determining the exact nature of the Soviet arsenal. Less mysterious was Soviet intent; the country’s doctrine was well established and was not subject to deviation. In the era of improvised everything, it’s easy to determine the capability of commercial components because you can Google them. In most cases, the capabilities of the weapons produced from those technologies can be deduced. Today, it is intent that’s harder to uncover. Is that individual walking down the street and talking on a cell phone a terrorist or a tourist? Intent gives the answer.

During the Cold War, we knew where our enemies lived and worked, and how they governed. Now, in many cases, we do not know who our enemies are, let alone their leadership structure. A primary challenge today is that of network discovery: Who knows who? Who works for whom? For the most part, our ISR systems remain optimized for “soda straw” collection on known entities at known locations. That approach cannot provide the intelligence picture required to defeat networks.

Adversaries are getting better at improvising, and so must we. To innovate effectively, the U.S. military has to ensure that our research and development base can improvise rapidly and experiment to create new capabilities.

In the past, the technologically disadvantaged side in asymmetric warfare often improvised through brute force or stealth. Swarms of kamikaze pilots tried to overwhelm Allied ship defenses during World War II. In Korea and Vietnam, our adversaries usually fought conventionally, but at times they tried to overwhelm the U.S. technological advantage with superior numbers. Today, the capabilities and easy availability of modern technology makes for an even more dangerous environment.

Cell phones, mass e-mails, streaming videos and text messages are just a few methods adversaries could use to rapidly assemble deadly versions of today’s “flash mobs” — groups of people who assemble to engage in odd acts in front of onlookers. Those technologies can be supplemented by the use of rules disseminated in advance among military-age civilian men, such as: “If you hear shooting, grab your gun, head toward the sound, and start shooting at Americans.” U.S. troops in Afghanistan and Iraq were sometimes surprised at how quickly mobs of people were able to appear during conflicts. Communications technology can enable “improvised command and control” to rapidly assemble an “improvised army.”

At sea, small, fast boats could swarm naval ships, testing the limits of short-range countermeasures and making long-range weapons ineffective. The severe damage an explosive-laden rubber dinghy inflicted on the destroyer Cole in 2000 warns against minimizing this threat. In addition, military and homeland security planners are concerned with other seaborne threats: uninspected cargo containers, or the semisubmersibles used by Caribbean drug smugglers. These seaborne threats can be considered an “improvised navy.”

Similarly, the proliferation of small unmanned aerial vehicles creates new challenges, particularly because most Cold War air defense systems are designed to detect larger, faster targets. These new types of airborne threats we consider a potential “improvised air force.”

Moving forward, commercial space exploration and micro satellites built by students imply that space may not remain a domain restricted to a few major powers. Even without space access, imagery and mapping tools, such as Google Earth and MapQuest, give adversaries an intelligence capability far beyond what was available 10 years ago. Training and recruitment can also be improvised through Internet chat rooms and online software games. These new asymmetric ISR threats are “improvised military intelligence.”

The challenge for the U.S. lies not only in identifying how and what can be done to counter these technologies before they become threats, but doing so within current acquisition cycles.

So, how do we regain our ability to “tinker” in the pursuit of national security? Defending against “improvised everything” will require improvisation-friendly designs and reforms to the acquisition system, including its incentive structure.

Reusing or “repurposing” old equipment is nothing new to the military. However, to innovate effectively, the military has to ensure that our research and development base increases its ability to rapidly improvise and experiment to create new capabilities.

New technologies used for intelligence, surveillance and reconnaissance are continually becoming available while existing technology can be used in new ways. If expensive military assets can be repurposed, vital capabilities can be rapidly created for much less cost than may be achievable under the traditional acquisition process.

Often, the cost of repurposing is orders of magnitude less than that of developing a new system. Many commercial imagery satellites originally were placed in orbit for limited, specific purposes. As these systems have become increasingly available, customers have used their imagery for unanticipated purposes, including fighting forest fires and searching for evidence of oil field depletion, archeological artifacts, downed aircraft and lost explorers.

C4ISR systems were difficult to repurpose when they had their own dedicated computers, satellites, operating systems and communications links. Today’s net-centricity provides access to a variety of sensors, allowing for the flexibility to quickly reuse and combine capabilities. It is now possible to repurpose ISR systems on the fly.

Companies already provide impressive capabilities in areas such as space surveillance, unmanned aviation and integrated circuit development. If these technologically sophisticated assets could be repurposed, the savings could be huge. Even more importantly, the needed capability could be deployed rapidly, through innovation and improvisation, rather than taking the decade or more a major Pentagon acquisition program might require.

But repurposing alone is insufficient. We need to ensure emerging systems are “improvisation-friendly” from the start. This requires a new approach to system design. New capabilities should be built for general purpose, unanticipated use. Flexible higher-level capabilities can be built on top of existing ones in a modular fashion.

Every high-performance air-to-air fighter aircraft, for example, has been used during its life cycle for reconnaissance missions. And every “pure” air-to-air fighter has ended up playing a major role in ground attack. Improvisation-friendly design would mean building new defense platforms to be fungible in a net-centric battle space as sensors, weapons or logistics conduits.

Fundamentally, the acquisition incentive system itself must be transformed to foster invention and improvisation throughout the technology and platform life cycle similar to the way commercial markets provide incentives for innovation. Policy makers must explore new ways to empower groups of smart people to invent or improvise capabilities from existing technologies. Today, the U.S. leads the world in professionally managed, high-technology R&D. We have state-of-the-art research labs. But what about our ability to combine the latest knowledge and training with rapid improvisation and experimentation, like the Wright Brothers tinkering in their bicycle shop?

The ponderous defense procurement enterprise cannot match the global free markets when it comes to innovation, speed to market and the ruthless destruction of flawed solutions. We ignore the message — and the products — of the global markets at our own peril.

Allan Steinhardt is a radar scientist and former program manager at the Defense Advanced Research Projects Agency. He is now a principal at the Booz Allen Hamilton consulting firm. David G. Smith is a defense and homeland security consultant for Booz Allen Hamilton. He has taught Civil War history at George Mason University.