Defense Primer: Army Multi-Domain Operations (MDO)

Defense Primer: Army Multi-Domain Operations (MDO)

Defense Primer: Army Multi-Domain Operations (MDO)

Updated December 8, 2025 (IF11409)

Overview

As an operational concept, Multi-Domain Operations (MDO) influence what types of weapon systems and equipment the Army procures, what types and numbers of soldiers are needed, the organizational structure of the Army, and what type of training is required—all significant congressional oversight concerns.

What Are Multi-Domain Operations (MDO)?

According to the Army's Field Manual (FM) 3-0 Operations dated March 2025,

Multidomain operations are the combined arms employment of joint and Army capabilities to create and exploit relative advantages to achieve objectives, defeat enemy forces, and consolidate gains on behalf of joint force commanders. Employing Army and joint capabilities makes use of all available combat power from each domain to accomplish missions at least cost.

Multidomain operations are the Army's contribution to joint campaigns, spanning the competition continuum. Below the threshold of armed conflict, multidomain operations are how Army forces accrue advantages and demonstrate readiness for conflict, deterring adversaries while assuring allies and partners. During conflict, they are how Army forces close with and destroy enemy forces, defeat enemy formations, seize critical terrain, and control populations and resources to deliver sustainable political outcomes.

Why Did the Army Adopt MDO?

MDO is described in a December 2018 Army publication, The U.S. Army in Multi-Domain Operations 2028. The Army developed MDO in response to the 2018 National Defense Strategy which shifted the previous focus of U.S. national security from countering violent extremists worldwide to confronting revisionist powers—primarily Russia and China—that are said to "want to shape a world consistent with their authoritarian model—gaining veto authority over other nations' economic, diplomatic, and security decisions." According to The U.S. Army in Multi-Domain Operations 2028,

China and Russia exploit the conditions of the operational environment to achieve their objectives without resorting to armed conflict by fracturing the U.S.'s alliances, partnerships, and resolve. They attempt to create stand-off through the integration of diplomatic and economic actions, unconventional and information warfare (social media, false narratives, cyber-attacks), and the actual or threatened employment of conventional forces. By creating instability within countries and alliances, China and Russia create political separation that results in strategic ambiguity reducing the speed of friendly recognition, decision, and reaction. Through these competitive actions, China and Russia believe they can achieve objectives below the threshold of armed conflict.

How the Army Intends to Compete

Arguably, competition is a critical aspect of MDO because if conducted successfully, conflict might be avoided. According to U.S. Army Chief of Staff Paper #2, The Army in Military Competition, dated March 1, 2021, the Army competes in three ways:

Narrative competition is reflected in the rise and fall of a country's reputation based on general perceptions of its strength, reliability, and resolve. The Army contributes by being a lethal, competent, credible force and being recognized as such by allies, partners, and adversaries.

Direct competition encompasses the full range of competitive activities, from the lowest intensity competition below armed conflict through general state conflict. In direct competition, the objective is to create leverage for the United States and to deny leverage to adversaries.

Indirect competition's objective is to gain advantage (or deny it to the adversary). This objective is in contrast to the more forceful concept of leverage in direct competition. The Army contributes by offering a range of credible options for policymakers.

Some of these options include overseas exercises, security cooperation, security force assistance, military-to-military exchanges, overseas basing, intelligence sharing, and disaster relief. In this regard, indirect competition is not a "new" operational concept but instead a "re-designation" of traditional activities short of armed conflict. Army leadership believes if the Army and the other Services prevail in these "competitions," U.S. national security objectives should be achieved.

How MDO Is Intended to Work

The Army's central idea is to prevail by competing successfully in all domains short of conflict, thereby deterring a potential enemy. If deterrence fails, Army and Joint forces are to

Penetrate enemy anti-access and area denial (A2/AD) systems (layered and integrated long-range precision-strike systems, littoral anti-ship capabilities, air defenses, and long-range artillery and rocket systems) to enable strategic and operational maneuver of U.S. forces.

Dis-integrate—disrupt, degrade, or destroy A2/AD systems to enable operational and tactical maneuver of U.S. forces.

Exploit the resulting freedom of maneuver to achieve operational and strategic objectives by defeating enemy forces in all domains.

Re-compete—consolidate gains across domains and force a return to competition on favorable terms to the United States and allies.

How Will MDO Change the Organization of the Army?

As part of the release of The U.S. Army in Multi-Domain Operations 2028, an Army official explained to CRS that specific Army echelons are to be given different "problems" to address under MDO. Existing Divisions and Corps are to be tasked with fighting and defeating specific components of the enemy's system. As such, the Army will no longer organize or center itself on Brigade Combat Teams (BCTs) as it did under previous National Defense Strategies. Under the previous BCT-centered organizational construct, Divisions and Corps had a limited warfighting role, but under MDO, Divisions and Corps headquarters are to return to their historic warfighting roles, in which they employed subordinate units and allocated Corps and Division-level assets to support subordinate units. To support MDO, the Army is also creating five Multi-Domain Task Forces (MDTFs). MDTFs are to be theater-level units to coordinate effects and fires in all domains against A2/AD networks.

How Will MDO Affect Army Modernization?

According to an August 2022 Army report to Congress in response to S.Rept. 117-39 to accompany S. 2792, the National Defense Authorization Act for Fiscal Year 2022, MDO-specific modernization plans are to include the following:

The portion of the Total Force that will undergo focused signature-modernization includes three theater headquarters, four corps, six divisions (including one Army National Guard [ARNG]), and 25 BCTs (including five in the ARNG). The balance of the Army's combat forces—five Regular [Active] Army and seven ARNG Divisions—are to be modernized after 2030, depending on the progress of the Army's focused modernization effort and fiscal considerations.

Concerns with the Army's MDO Doctrine

While the Army continues to emphasize the importance and necessity of MDO others have expressed concern. One commentary from 2024 notes,

Despite its faddishness, or perhaps because of it, the multi-domain operations concept is now guiding the transformation and modernization of Western armed forces and of their peers. Yet, there are real concerns about whether multi-domain operations will mature into a fully functional warfighting concept or whether it will go by the wayside like effect-based operations in the past.

The authors further suggest:

New concepts are often highly optimistic, uncoordinated with other services and allies, and lack any clear theory of success.

Most concepts fall prey to technological overconfidence, particularly in the field of communications. Assured connectivity in combat is central to nearly all multi-domain operations.

The effective implementation of MDO depends on the availability of mature technologies, in sufficient numbers, deployed by trained and ready forces.

Experiences in Ukraine and the Middle East do not necessarily conform the how MDO postulates future conflict and that "claims to be able to see all, move quickly, and strike anywhere in order to rapidly resolve a conflict with minimum civilian impact are once again being challenged."

The Army's Perspective

Army discussions with CRS regarding the previously-cited commentary challenge the aforementioned assertions noting that, among other things,

MDO contains an explicit theory of victory (compete, penetrate, dis-integrate, exploit, and re-compete) and has been developed with participation from all services, Five Eyes partners, and Joint Staff representatives since 2021.

Regarding technological overconfidence and communications, the Army states that denied, degraded, intermittent, and limited conditions are already an assumed feature of Army wargaming against peer threats. The Army reports pursuing multiple mitigations across doctrine, organization, training, materiel, leadership, personnel, facilities, and policy (DOTMLPF-P), not relying solely on technological solutions.

Concerning whether current conflicts contradict MDO assumptions, the Army assesses recent operations in Ukraine and the Middle East show greater battlefield visibility, longer-range strike capabilities, and limited sanctuary for forces. The Army views these trends as broadly consistent with conditions anticipated in MDO.

On critiques that MDO does not fit existing political or organizational structures, the Army notes that service concepts outline how forces might operate and develop capabilities in support of joint objectives. They are not strategies and therefore do not assign responsibilities across other departments or instruments of national power.

Related CRS Products

CRS In Focus IF11797, The Army's Multi-Domain Task Force (MDTF), by Andrew Feickert.