What is the purposeful reliance by one service on another services capabilities to maximize the complementary and reinforcing efforts of both?

Interoperability and Interdependence

(This is the first in a series on the capabilities US, allies, and partners need for collaboration to achieve the security vision described in the 2018 NDS.)

The 2018 National Defense Strategy (NDS) calls us to “Strengthen alliances and attract new partners” by deepening interoperability to compete, deter, and win in today’s environment. Combining the strengths of US, ally, and partner forces during operations increases the total forces available to coalitions, adds niche partner capabilities not available in US forces, and shares burdens across participating nations. Although the NDS calls for interoperability and postulates concepts for interdependent forces, the terms “interoperability” and “interdependence” are often misapplied. This article defines interoperability and interdependence as elements necessary to implement the 2018 NDS, describes a modern framework for interoperability based on common networks and data, and describes changes needed in US FMS practices to fully leverage the concepts.

Interoperability. The 2018 NDS calls for interoperable forces “able to act together coherently and effectively to achieve military objectives” through common “operational concepts, modular force elements, communications, information sharing, and equipment.” JP 3–0 further defines interoperability as “the ability to act together coherently, effectively, and efficiently to achieve tactical, operational, and strategic objectives” (JP 3–0). The capabilities needed for forces to be interoperable have grown over time, and now include secure networks and interoperable data.

While “interoperability” used to be about partners procuring the right platforms and sensors, then training together, modern interoperability is about sharing increasing amounts of data over common networks. Sharing data over a common network allows partners to achieve high levels of shared understanding, such as through a Common Operating Picture (COP), which is the basis for combined command and control (C2) and tactical execution of agreed operational contracts between partners.

Sharing data starts with operating on a common network. JP 6–0 reflects that interoperability is “achieved among communications-electronics systems . . . when information or services can be exchanged directly and satisfactorily between them and/or their users.”

Once operating on the same network, interoperability continues with partners sharing mutually-accessible data according to common standards. Link-16 standards are an example of that sharing today. While current tactical datalinks share fully synthesized information in the form of track files, future systems will share system-level data which will enable software tools to discover threats that no single sensor could individually generate today.

Interdependence. JP-3–0 defines joint interdependence as “the purposeful reliance by one Service on another Service’s capabilities to maximize the complementary and reinforcing effects of both. (JP 3–0, pg IV-5).” While joint interdependence is defined, the concept of combined interdependence among allies and partners is not. Modifying the definition for a coalition context, interdependence among partners is the purposeful reliance by one partner on another partner’s capabilities to maximize the complementary and reinforcing effects of both.

Combined interdependence has two aspects, dependence on partner capacity and dependence on partner capability. The first form of interdependence is reliance on partner capacity to fill shortfalls in US capacity needed to accomplish a mission. Examples of reliance on partner capacity include needing partner fighters to fly combat air patrols to fully resource a defensive air plan, or needing partner Patriot systems to fully defend US forces in a region. Interoperable partner capacity can significantly reduce risks for commanders during operations.

The second form of interdependence is reliance on partner capabilities to fill capabilities that US forces don’t have, or capabilities that are unsourced for the mission. Examples include advanced air surveillance capabilities, niche cyber capabilities, or human intelligence networks in areas not developed by US intelligence agencies. Partners offer access to significant capabilities which enable commanders to select different courses of action than those available with US forces operating unilaterally, and also reduce risks for US forces and missions.

Just like we set standards for exercises and training and build partners into our exercises from the start of planning, we need to build allies and partners into our future network and data structure, and define a data architecture that fully integrates and leverages partner data. To achieve data-interoperability with partners, we can “build-in” or “bolt-on” partners into the new data infrastructure. However, the high levels of data exchange needed for advanced AI tools will be limited in “bolt-on” structures. Instead, we need to build allies and partners into our future JADC2 network and data infrastructure from the outset to maximize interoperability. Rapid IAMD developments in the Middle East and Europe offer significant opportunities to define the future network and data architectures that integrate allies and partners with the highest level of interoperability.

Conclusion. We will depend on the interoperable capabilities of allies and partners to achieve the vision cast by the 2018 NDS. Partner capabilities like air-to-air fighters and missile defense increase the forces available to coalitions and the collective operational capacity of like-minded nations working together. We will also increasingly depend on specific partner capabilities to do our missions and reduce risks, and rely on allies and partners to bring specific niche capabilities that US forces don’t have to coalition operations. To fully leverage partner capabilities, we need to build allies and partners into our future networks and data architecture from the beginning, modernize FMS practices for the Information Age, and make best use of limited development funds by balancing the risks of proliferation with the high costs needed to protect “state of the world” 4th-generation technologies. By increasing the operational capabilities of allies and partners through a holistic approach, we can achieve the vision of stability and security envisioned in the 2018 NDS.