The scope and scale of today’s leading defense challenges require too much of any single defense organization; there simply isn’t enough time, money, or people within a defense department or ministry to effectively address the range of challenges. As a result, many of the strategies that defense departments and ministries are devising to combat today’s challenges demand significant coordination with other government agencies, other nations, and even commercial companies. Take US Cyber Command’s new strategy of “defend forward” as just one example. Designed to counter gray zone cyberthreats, this strategy involves the placement of US military cyber experts in foreign countries to disrupt attacks headed for the United States. This strategy demands coordination with host nation governments, their military and security agency cyber forces, and familiarity with regional commercial technology companies.6
But most militaries are just not organized to enable the coordination required for today’s defense challenges. For example, despite the US Army’s commitment to international interoperability and the many interoperability efforts underway across NATO, ABCANZ Armies, Africa, and Asia, there is only one purpose-built Army unit at the Service Component Command level designed for interoperability—a 30-soldier Digital Liaison Detachment providing digital information-sharing capabilities to allied and multinational forces.7 When militaries aren’t organized for interoperability, they must create it by patching together existing processes and activities not designed for interoperability. The patchwork approach can add costs, create capability dependencies, present capability gaps and seams, and remain inflexible to diverse defense challenges.8
Successful strategies against leading defense challenges, then, must include an expanded understanding of interoperability. Exactly what kind of interoperability may vary by the specific threat and country involved, but nearly every strategy for future threats will require defense organizations to work with organizations outside of their comfort zone.
New threats demand renewed focus
From gray zone threats to near-peer conflict, adversary strategies are focused on taking advantage of weaknesses or eliminating the critical nodes that friendly militaries rely on. A single exploitable weakness can mean the difference between an effective defense or not. For example, in peer warfare, militaries are likely to find themselves facing adversaries waging “systems confrontation warfare” designed to cripple the very national and strategic systems a modern military relies on, including communications, logistics, and command and control.9
For the United States, a recent Department of Defense wargame showed traditional ways of operating against an enemy targeting critical military systems meant the loss of communications and the battle.10 The wargame hosted to test the United States’ Joint Warfighting Concept designed around interservice interoperability, showed that traditional assumptions—for example, that information will be ubiquitous—led to fatal dependencies easily exploited by the adversary.
A similar story emerges from other threats such as gray zone influence campaigns. These campaigns, such as that carried out by Russia during the 2017 German election, target democracies’ critical node of public perception through a variety of nefarious means.11
Interoperability with other government agencies, industry, and allies and partners acts as an important hedge against these adversary strategies by creating affordable redundancies and expanding operational choices. For example, in the case where a peer adversary targets critical communication nodes, interoperability with an allied nation can provide alternative communications pathways that provide redundancies and challenge the adversary by requiring it to attack more targets. For example, the United States has recently recognized that the very expensive but few military satellites it relies on, pose a risk to military operations during conflict because such a small number of critical systems makes for ideal targets.12 As a result, US Strategic Command is pursuing a new communications architecture prototype that will allow communications to easily transition from military to allied to commercial satellite communications in the event one of the satellites is disrupted.13
Similarly, interoperability with commercial technology companies can help provide defense and security agency organizations more avenues to respond when confronting an online mis-/disinformation campaign. Together, these types of interoperability increase operational resilience and options that match the increased scope and scale of today’s defense challenges.
Militaries have used interoperability in the past to create exactly this resilience. For example, the proximity fuse, a top-secret radar-based artillery fuse, was originally developed in Britain during the early stages of World War II. But under the strain of the Battle of Britain, the United Kingdom was having trouble operationalizing the technology. By making the research available to the United States, the British were able to tap into not only new sources of supply beyond the reach of German bombers, but also US research capacity, resulting in more and improved proximity fuses reaching British forces. These fuses turned out to be critical in defeating the V-1 flying bomb threat to British cities.14
In this way, interoperability doesn’t just improve tactical operations; it becomes an important contributor to strategic advantage. In addition to being a technological development accelerator, interoperability can also provide the resilience critical to mitigating the dangers posed by today’s myriad of threats. This doesn’t require allies and partners to change in the same way, have the same equipment, or even adopt uniform concepts of operation. Instead, it would require leveraging allies and partners, industry, and other government organizations based on their strengths.
Reassessing the value of interoperability
Traditionally the value of interoperability was twofold: It could help create coalitions that gave military action greater political legitimacy, and it could improve some operational efficiency. The problem is that interoperability also involves significant costs that can counteract those benefits. It takes money to buy interoperable radios; it takes extra time and effort to coordinate combined operations, and so on.15 Yet many of the defense challenges of the last 20 years, such as counterinsurgency operations or foreign disaster relief, required relatively limited interoperability. When the cost is high but the strategic and operational return on investment is low—with some exceptions, as is the case for NATO while Russia poses a threat—defense organizations don’t have an incentive to increasingly organize around the idea, leaving interoperability efforts to stagnate around select functions or allies and partners. As a result, the benefit of enhancing interoperability to another level or among a wider range of intranational and international partners is rarely seen as justifying the significant costs.
So what is different today? Simply put, interoperability helps provide a strategic advantage in facing today’s increasingly complex defense challenges. With new threats targeting the core systems of friendly countries, not just militaries but political systems, infrastructure, and more, the flexibility and resilience that interoperability can provide become a critical element of advantage. But to realize an advantage, defense organizations need to mature beyond traditional forms of interoperability to include other government organizations, private industry, and the various politics, policies, and economics that come with broader coordination. Today’s defense challenges may resemble those of the past, but their character is new. To keep pace, interoperability must also take on a new character: one that is more inclusive and sown into the fabric of defense organizations.
A modern take for modern challenges
Militaries have cultivated interoperability throughout history. The first battle ever recorded in history featured a large coalition force composed of Canaanite vassal states.16 In the nearly 3,500 years since that battle, interoperability was developed to help preidentified nations work together. NATO represents this line of thinking. Its standards and training have been critical to multinational coalitions from the first Gulf War to Iraq, Afghanistan, and Syria.17 But NATO is still built on a vision of interoperability among a predefined group of states, and principally along military lines. If a non-NATO member military wishes to take part in NATO training, it must procure the equipment NATO requires to be interoperable, such as radios and the associated communications security software.18 But procuring specific radios for a training exercise or following strict approval processes to access security software describes a strict form of interoperability where other militaries conform to NATO rather than NATO meeting other militaries where they add value. It connotes an important element of military-to-military tactical interoperability, but it is in and of itself a limited expression of what interoperability could and should be.
Today’s defense challenges often require a more flexible vision of interoperability. The exact participants of a coalition may not be known ahead of time; key participants and/or partners may not even be militaries but commercial technology companies or NGOs or private logistics providers. Even the challenges themselves are variable. Every defense challenge requires interoperability, but not necessarily the same level of interoperability in every function. Defending a rules-based international order, for example, may demand high levels of workforce interoperability with personnel conversant in the military, commercial, and international resources needed to defend the values and institutions the rules-based international order is built on. Yet, it likely will not require the same close integration of acquisition systems needed in near-peer or limited-scale warfare. This means that rather than nations simply reaching for maximum interoperability in every function for every threat, nations and their defense organizations should tune their interoperability efforts to their specific circumstances.
In facing peer warfare, gray zone threats, defending the rules-based international order, or limited-scale warfare, the goal is not to develop interoperability as a static model, but to create a defense organization that can adjust its interoperability to missions, allies, and technology. To create such an organization requires prioritizing investments in interoperability across four military functions (figure 1). A defense organization should balance how it chooses to develop its interoperability based on the resources at its disposal, its ranking of priorities, and the complementarity of its military, commercial, and government partners, the goal being to achieve enough national interoperability across defense challenges to gain a relative advantage over each priority and situation.