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Defense Transportation: DOD Can Better Leverage Existing Contested Mobility Studies and Improve Training

GAO-21-125 Published: Feb 26, 2021. Publicly Released: Feb 26, 2021.
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Fast Facts

In a potential conflict, a hostile country could prevent the military from rapidly moving equipment and personnel from the U.S.

What is DOD doing to mitigate the challenges of this "contested mobility"?

DOD's contested mobility studies have led to 60 recommendations. Officials believe that some have been implemented, but DOD isn't tracking these recommendations.

DOD has updated some training to help address contested mobility, but it hasn't yet updated the sealift training. Major operations rely on sealift ships for most of their cargo.

We recommended designating an oversight entity to track recommendations and updating the sealift training.

Soldiers guide an Army vehicle off of a military sealift ship.

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What GAO Found

From 2016 through 2019, the Department of Defense (DOD) conducted or sponsored at least 11 classified or sensitive studies on contested mobility— the ability of the U.S. military to transport equipment and personnel in a contested operational environment. The studies resulted in more than 50 recommendations, and DOD officials stated they believed that some of the recommendations had been implemented. However, officials did not know the exact disposition of the recommendations, as they are not actively tracking implementation activities. Further, no single DOD oversight entity evaluated the studies' recommendations and tracked implementation across the department. As a result, DOD may be missing an opportunity to leverage existing knowledge on mobility in contested environments across organizations, and strengthen its mobility efforts for major conflicts as envisioned in the National Defense Strategy.

DOD has updated aspects of wargame exercises and mobility training to prepare for a contested environment, but has not updated training for the surge sealift fleet—ships owned by DOD and the Department of Transportation's Maritime Administration (MARAD) and crewed by contracted mariners. These crews are primarily trained and qualified to operate the ship, but receive limited contested mobility training. While DOD has updated air mobility training and other aspects of mobility training, sealift crew training requirements have not been updated by DOD and MARAD to reflect contested environment concerns because DOD has not conducted an evaluation of such training. Since sealift is the means by which the majority of military equipment would be transported during a major conflict, it is important that crews be trained appropriately for contested mobility to help ensure that ships safely reach their destinations and complete their missions.

C-17 Performing Defense Maneuvers

C-17 Performing Defense Maneuvers

DOD has begun to mitigate contested environment challenges through improved technology and related initiatives. The Navy is acquiring improved technologies to deploy on surge sealift ships and replacement ships. The Air Force is equipping current mobility aircraft (see photo above) with additional defensive technologies and planning for the development of future replacement aircraft. According to U.S. Transportation Command, the command is revising its contracts with commercial partners to address cyber threats, and funding research and development projects that address contested mobility concerns. Many of these efforts are nascent and will take years to be put in place.

Why GAO Did This Study

China and Russia are strengthening their militaries to neutralize U.S. strengths, including mobility—the ability of U.S. military airlift and air refueling aircraft and sealift ships to rapidly move equipment and personnel from the United States to locations abroad to support DOD missions.

Senate Report 116-48 included a provision for GAO to review DOD's ability to operate in a contested mobility environment. This report assesses the extent to which DOD has studied contested mobility and tracked the implementation of study recommendations, assesses the extent to which DOD has revised its training to incorporate contested mobility challenges, and describes the technologies that DOD uses to mitigate contested mobility challenges.

GAO identified contested mobility studies conducted or sponsored by DOD; evaluated DOD's processes for monitoring implementation of study recommendations; analyzed training and exercise documents from DOD combatant commands, the Air Force, and the Navy; and reviewed DOD plans for technological improvements to its mobility forces.


GAO recommends that DOD designate an oversight entity to track the implementation of study recommendations, and that DOD and MARAD evaluate and update sealift training. DOD and the Department of Transportation concurred or partially concurred with each recommendation. GAO believes each recommendation should be fully implemented, as discussed in the report.

Recommendations for Executive Action

Agency Affected Recommendation Status
Department of Defense The Secretary of Defense should ensure the designation of an oversight entity to evaluate the results of contested mobility studies and track the implementation of recommendations deemed appropriate. (Recommendation 1)
Closed – Implemented
In our February 2021 report, DEFENSE TRANSPORTATION: DOD Can Better Leverage Existing Contested Mobility Studies and Improve Training (GAO-21-125), we found DOD had studied contested mobility but had not systematically addressed the studies' recommendations. Specifically, from 2016 through 2020, DOD and its think tanks conducted at least 11 classified or sensitive studies on various aspects of contested mobility. While DOD used information from the studies, it had not systematically implemented and tracked the studies' recommendations. We recommended that the Secretary of Defense ensure the designation of an oversight entity to evaluate the results of contested mobility studies and track the implementation of recommendations deemed appropriate. Since then, U.S. Transportation Command (TRANSCOM) has taken the lead in addressing our recommendation. TRANSCOM compiled the recommendations from prior contested mobility studies and evaluated each one by making specific remarks as to its disposition and/or potential. According to TRANSCOM officials, they will continue to evaluate studies as part of their process for preparing for future meetings of the Joint Deployment and Distribution Executive Board. By reviewing recommendations from past contested mobility studies DOD can be sure that they have leveraged existing knowledge on contested mobility to address challenges before they inhibit DOD's ability to conduct mobility during major conflicts.
Department of Defense The Secretary of Defense, in coordination with the Chairman of the Joint Chiefs of Staff, should ensure that the Secretary of the Navy and the Commander of U.S. Transportation Command, in coordination with the Department of Transportation's Maritime Administrator, evaluate surge-sealift crew training and related guidance to ensure it reflects the skills and competencies that might be required of sealift crews in a contested environment. (Recommendation 2)
Closed – Implemented
DOD concurred with this recommendation and has taken action to address it. Specifically, in July 2021 U.S. Transportation Command gave guidance to Military Sealift Command (MSC) and the Department of Transportation's Maritime Administration (MARAD) on the strategic sealift program, which includes the surge sealift crews. The guidance stated that MSC will define training requirements, skills, and competencies required of contract mariners serving on strategic sealift vessels during naval operations and in contested environments. Based on updated strategic sealift guidance, MSC developed the skills and competencies required for sealift in a contested environment, according to Joint Staff. Joint Staff also said that the requirements for operations in a contested environment were discussed with both Navy and MARAD. Finally, MSC assisted in the development of the Navy's instruction 3501.199D, which was updated in March 2022. This updated instruction described required operational capabilities and projected operational environment for the strategic sealift ships. It states that strategic sealift will generally be operating in low-density threat operations, yet will retain the capability to continue operations if damaged. The most demanding operating environment anticipated for strategic sealift ships is at sea, during wartime, in coordination with designated joint and allied forces, including operations involving coordination of land and sea-based aviation because mobility will presumably be in contested environments. By evaluating and updating surge-sealift required operational capabilities, DOD is better positioned to ensure mariners are prepared for their missions and its surge sealift is ready to transport equipment during major military operations.
Department of Transportation The Secretary of Transportation should ensure that the Maritime Administrator, in coordination with the Secretary of the Navy and the Commander of U.S. Transportation Command, updates surge-sealift crew training, as appropriate and feasible, to reflect the results of the training evaluation conducted by DOD. (Recommendation 3)
In its comments, the Department of Transportation partially concurred with our third recommendation for MARAD. Until DOD addresses Recommendation 2, the Department of Transportation cannot address Recommendation 3. In its original comments to our report, the Department of Transportation stated that if DOD identified and documented requirements, and developed and implemented a comprehensive, relevant and structured training schema, MARAD would be in a position to determine if updates to surge sealift crew training were feasible and appropriate in terms of the level of resources and coordination required to implement such training.

Full Report

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Air-refueling tankersAircraftCommunicationsDefense logisticsDefense transportationIn-flight refuelingLogisticsMilitary communicationMilitary forcesNational defenseNavy shipsStrategic sealiftTransportation