An Army Overseas

Expeditionary Maneuver through the Maritime DomainDePuY-2016-award-2nd

Lt. Col. Trent J. Lythgoe, U.S. Army

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The paramount concern … of maritime strategy is to determine the mutual relations of your army and navy in a plan of war.

—Julian Corbett

An expeditionary Army is essential to American security. America has historically depended on expeditionary forces to defend worldwide security and economic interests. Today, increased globalization, along with the geographical dispersion of America’s top security challenges (China, Russia, North Korea, Iran, and transnational terrorism), make globally responsive expeditionary forces more necessary than ever.1 The U.S. Army, however, is hard-pressed to meet these challenges for a variety of reasons.2 The Army’s legacy force-flow model (reception, staging, onward movement, and integration [RSOI]) depends on large airfields and vulnerable deepwater seaports. America’s adversaries are increasingly positioned to exploit this weakness using anti-access warfare.3 Even so, lulled by successes in the Gulf War (Operations Desert Shield and Desert Storm) and elsewhere, the Army continues to rely on RSOI.

The Army must return to its roots as an expeditionary force to meet the challenges of today’s security environment, particularly the challenges of anti-access warfare. The joint force needs Army forces capable of expeditionary maneuver; rapidly deployable land forces that can maneuver over strategic distances, transition to the offense quickly, and fight in austere conditions. Expeditionary maneuver will allow Army forces to attack at unexpected times and locations, creating multiple entry points for follow-on forces and creating multiple dilemmas for the enemy.4 Expeditionary land forces can bypass enemy anti-access defenses emplaced to deny entry via airfields and ports.

Central to successful expeditionary maneuver is restoration of the Army’s maritime expeditionary capabilities. Expeditionary maneuver requires the ability to sealift large, heavy Army formations, move them ashore, and rapidly transition to combat operations. For such a restoration of maritime expeditionary capabilities to be successful, certain joint capabilities need to be prioritized. This article outlines six joint capabilities required to enable expeditionary maneuver: sea control, using the sea as maneuver space, capable initial entry forces, rapid reinforcing forces, ship-to-shore connectors, and joint force integration.

A Brief History of Expeditionary Warfare

The whole power of the United States to manifest itself in this war depends upon the power to move ships across the sea. Their mighty power is restricted, it is restricted by those very oceans which have protected them. The oceans which were their shield have now become a bar, a prison house, through which they are struggling to bring armies, fleets and air forces to bear upon the great common problems we have to face.

—Winston Churchill5

America is a maritime nation; a strategic island bordered by two oceans and reliant on overseas trade.6 Historically, maritime powers have depended on expeditionary forces to secure remote national interests, and the United States is no exception. During peacetime, expeditionary forces secure trade routes and global interests. In times of war, they allow maritime powers to use expeditionary warfare in an “away game” strategy (i.e., fight somewhere else other than on the homeland territory). By fighting abroad, expeditionary forces spare the homeland from destruction.7

Modern joint expeditionary warfare emerged at the end of the eighteenth century as a powerful strategic advantage. Moving land forces by ship had been part of warfare for thousands of years. But, in the late 1700s, advances in sailing technology allowed maritime powers to orchestrate campaigns using expeditionary sea and land power together as mutually supporting joint forces. Newly empowered maritime powers could not only protect interests beyond their shores but could also execute “peripheral campaigns” to attack enemies indirectly at multiple points or along multiple axes.8

British operations from 1805 to 1815 are early cases in point. After gaining sea control at Trafalgar, British expeditionary forces seized French territories in the Caribbean, depriving the French regime of vital revenue.9 Meanwhile, British army operations on the Iberian Peninsula, supported by the Royal Navy, tied down large numbers of French troops, preventing Napoleon from reinforcing the continental fight in Russia and Germany.10

The United States likewise used joint expeditionary operations to further interests abroad. From 1800 to 1945, joint expeditionary operations played a prominent role in nearly every major U.S. conflict, including the Mexican War, the Civil War, the Spanish-American War, and World War II.11 America’s first large-scale expeditionary operation was the 1847 Mexico City campaign. Army Gen. Winfield Scott’s eleven-thousand-strong force conducted a forcible entry at Veracruz, and then pushed west to capture Mexico City. The U.S. Navy supported the campaign by providing troop transport and naval gunfire during amphibious operations and by keeping sea lines of communication open as Scott pushed inland.12

Elsewhere, the Pacific “island hopping” campaign (1943–45) is a classic example of joint expeditionary force application against the Japanese anti-access strategy in the western Pacific. Allied land forces, maneuvering by sea and supported by naval forces, bypassed Japanese strongholds and seized strategically important islands, which became support bases for aircraft and logistics. This, in turn, enabled joint air, sea, and land forces to project even deeper into enemy territory. The ability of Allied forces to mutually reinforce their efforts across land, air, and sea domains (and the Japanese forces’ inability to do so) was a critical factor in Allied success.13

American expeditionary capability reached its peak in 1945, at which point the United States was able to project and support a land force of over 1.3 million soldiers.14 As World War II ended, however, U.S. expeditionary capabilities were intentionally drawn down. Expeditionary posture gave way to forward-positioned forces that could deter and respond to Cold War threats in Europe, and later in Korea.15 These forward garrisons provided assured access to key infrastructure, which would allow reinforcing forces to flow into theater. Maintaining assured access and optimizing the RSOI process replaced expeditionary capability as the centerpiece of U.S. force projection strategy. However, as a result, expeditionary capabilities naturally atrophied.16


Desert Storm: A Strategic Inflection Point

With victory, all of the army’s habits, procedures, structures, tactics, and methods will indiscriminately be confirmed as valid—or even brilliant—including those that could benefit from improvement or even drastic reform.

—Edward Luttwak17

The magnificent performance of the entire coalition and the totality of the victory clearly establishes the tenor of after action discussions as absolute success.

—U.S. Central Command Desert Storm After Action Review18

The Gulf War (1990–91) was a military-strategic inflection point for U.S. forces and would-be adversaries alike.19 By 1990, the U.S. Army had honed the RSOI force-flow model during years of Cold War preparation. But, when Saddam Hussein invaded Kuwait in 1990, the Army faced a new problem. It had to deploy large numbers of heavy forces to a theater without forward garrisons. With little expeditionary capability, Army forces needed modern ports and airfields. The cooperation of Saudi Arabia, which had modern infrastructure close to the area of operations, became indispensable. Fortunately, the Saudis were willing allies and agreed to let U.S. forces use Saudi facilities.

The Gulf War deployment became a de facto test of the RSOI model in a post-Cold War conflict. History records the Gulf War as an overwhelming success. However, that assessment belies the fragility of the force flow that enabled that success. Over a period of eight months, the U.S. military flowed 576 ships and 10,002 aircraft into theater.20 This massive amount of cargo moved through only a few key sites: 96 percent of sea cargo flowed through just two ports and 78 percent of air cargo through five airfields.21 Had Iraq managed to destroy or degrade even one of these sites, the Gulf War could have been much more difficult for the coalition. Despite potentially fatal flaws, the Army embraced this new version of RSOI in which access agreements with regional allies replaced the forward garrisons of the Cold War.

Irrespective of the U.S. vulnerabilities that were not exploited, the swift expulsion of Iraqi forces from Kuwait was a wakeup call for U.S. adversaries. China, Russia, and Iran suddenly sensed they were far behind the United States in military capability. The U.S. advantages in technology and training were plainly evident. Adversaries simply could not compete with the United States at the operational or tactical level. But while the Gulf War framed the problem in stark terms for potential U.S. adversaries, it also hinted at the solution. U.S. forces depended on vulnerable ports and airfields to get into position. Iraq’s failure to contest coalition force flow in the Gulf War was a costly strategic error, and one that China, Russia, and Iran determined not to replicate.22 The obvious solution was an anti-access strategy designed to offset U.S. advantages by disrupting or defeating U.S. forces at a distance before they could bring their tactical and technological superiority to bear.23

Somewhat oblivious to the unique factors that had enabled its stunning victory, while adversaries were reorienting to an anti-access defense, the United States actually facilitated a diminishment of its expeditionary capabilities. One consequence was that U.S. forces spent the 1990s strategically adrift amid theoretical postulation and debate concerning a “Revolution in Military Affairs.” This theory predicted U.S. forces would enjoy air and sea supremacy in operations characterized by technology that would enable “perfect intelligence,” robust command, and long-distance precision strikes in future conflicts.24

Despite this flawed thinking, U.S. forces were successful, at least in terms of force flow, in a series of actions from 1991 to 2011. Major operations in the Balkans and Libya, as well as early operations in Afghanistan and Iraq, seemed to validate the Gulf War RSOI approach. In each instance, the United States continued to enjoy air and sea supremacy, willing regional allies, and unmolested force flow through ports of entry to which they were given access.25

In contrast, today the U.S. Army is now in a precarious position. It still relies on the twenty-five-year-old Gulf War RSOI model to move forces. But, whereas Iraq was ill prepared to face U.S. military forces in 1991, today’s adversaries have spent the last quarter century preparing to defeat the United States at a distance. To do so, they have developed effective anti-access capabilities, including antishipping weapons, integrated air defenses, long-range fires, counterreconnaissance, and asymmetric threats.26 In addition, the deepwater ports required for Army RSOI will almost certainly not be available (at least initially) in the next fight.27

As a result, in the event of a regional conflict, determined and well-prepared adversaries can be expected to attack our flow of forces with long-range fires, asymmetric forces, and even weapons of mass destruction.28 Furthermore, antiship and anti-aircraft systems, mines, surface and subsurface vessels, and asymmetric seaborne forces will make the surrounding littorals too dangerous for naval operations, much less the Military Sealift Command (MSC) and commercial vessels that typically move Army forces. Even ports distant from a location in which contingency operations are being considered may be untenable due to their being within the scope of enemy weapon attack. Moreover, adversaries can disrupt port operations at distant locations from the intended operational area using such asymmetric means as terrorist attacks, crime, cyberattacks, or fomenting labor disputes.


A Return to Expeditionary Maneuver

The proliferation of anti-access weapons and strategies means the U.S. Army’s next major operation is likely to be preceded by a counter-anti-access campaign. Although the initial phases will be strongly maritime in character, Army forces will nonetheless be essential.

In the event of a needed forced entry from the sea, it is expected that the coordinated and mutually reinforcing application of force across all domains will weaken, and eventually collapse, the anti-access defense. Expeditionary land forces are optimally used to attack or threaten at multiple locations, including anti-access nodes, forcing the enemy to dilute its defenses. Then, habitually, Army forces reinforce and exploit the initial success of marine amphibious operations to establish a lodgment. U.S. Army and U.S. Marine Corps (USMC) land forces then occupy or seize key terrain to enable freedom of maneuver for naval and air forces. Upon conclusion of the counter-anti-access campaign, expeditionary army forces facilitate the flow of follow-on forces by establishing expeditionary infrastructure and seizing previously denied ports and airfields.

This type of joint campaign requires the Army to be an expeditionary rather than a garrisoned force. The Army must be able to maneuver forces from the sea without reliance on ports, and potentially in contested areas.29 Expeditionary maneuver, as proposed by the Army Operating Concept, envisions an expeditionary army that can deploy and fight a mix of light, medium, and heavy forces for whatever duration and at whatever scale is necessary. These forces will maneuver over strategic distances, overcome or bypass anti-access defenses, and attack at unexpected locations to create multiple dilemmas for the enemy.30

The case for an expeditionary army is supported by historical precedent and the likely demands of future conflict. How the U.S. Army will operate in the future depends largely on the particulars of the conflict. That said, there are six key capabilities common to such operations that will underpin any successful joint expeditionary operation regardless of scenario.

Sea control. Sea control is the first prerequisite for successful expeditionary operations. Although clearly a Navy responsibility, the Army has a vested interest in sea control.31 It is worth noting that in 1989 the Navy had 592 active ships, while today it has 274.32 While quantity is not necessarily equivalent to effectiveness, Army leaders should nevertheless be concerned about the size of the Navy and advocate for adequate naval capability.

Using the sea as maneuver space. The Army must maneuver, rather than move, on the sea. Army forces must arrive at positions of advantage ready to fight, not just ready to offload. Equipment must be combat configured and units must have embarked with it. Once underway, commanders and staffs must be able to maintain situational awareness and conduct mission command. Units must be able to transfer troops, equipment, and cargo between vessels while still offshore to prepare for combat operations.

To achieve this, the Army must rethink the way it employs military and commercial shipping. The Army will likely not move on Navy ships. Nor will Army forces stage on amphibious assault ships; there are already too few for USMC requirements.33 Rather, the Army must adapt existing shipping for expeditionary operations. MSC large, medium-speed roll-on/roll-off vessels, normally used to move bulk-loaded Army equipment, could be modified to move combat configured equipment with troop berthing and a mission command suite. Other vessels have similar potential.

The expeditionary transfer dock, expeditionary mobile base, and expeditionary fast transport (formerly called the joint high-speed vessel) can all accommodate Army troops, equipment, and aircraft. Fortunately, efforts to adapt existing shipping along these lines are already underway.34 Although not fighting ships, these vessels could operate in a second echelon outside the threat zone. The joint force could use air and surface connectors to move between ships and from ship to shore, using the fighting ships in the amphibious ready group and carrier strike group as “lily pads,” if necessary. As the fight progresses inland and the threat lessens, second-echelon ships could move closer to shore.

Capable initial-entry forces. Initial-entry forces are essential in a counter-anti-access campaign. These forces establish lodgments at multiple entry points away from heavily defended infrastructure. Amphibious assault operations are likely to be the main effort during the initial phases. USMC amphibious forces are ideally suited to seize a lodgment through which seaborne Army forces could flow. Airborne, air assault, and special operations forces will likely operate simultaneously at offset objectives in order to present multiple dilemmas to the enemy and prevent the enemy from concentrating defensively at any one point. The threat of multiple entries will force the enemy to either thin its defenses along a large front, or accept weak areas based on an enemy risk calculus, thus providing additional opportunities to joint force commanders.

Rapid reinforcing forces. Initial-entry forces create an initial advantage using speed and surprise. However, entry operations must be quickly reinforced. Without rapid reinforcement, joint force commanders will be unable to exploit initial success and initial-entry forces may be defeated or destroyed. Current deployment times for Army forces are not fast enough for rapid reinforcement. Marine forces afloat, for example, may be ready to conduct entry operations in a matter of days or weeks after notification. However, under present circumstances, Army reinforcements could take up to ninety days to arrive.35

There are multiple ways the Army can reduce or close the gap. Designating rapid response forces, including light, medium, and heavy units, is a good start. But, improving expeditionary capabilities in the Army writ large is also necessary. The Army must shorten lengthy institutional deployment processes, increase combat loading for early responding forces, and reduce multi-modal transfers (two or more means of transport for a single cargo). Additionally, Army forces need expeditionary mission command capabilities and tailorable expeditionary sustainment packages. The Army should also reexamine its prepositioned equipment strategy, both in terms of composition (light, medium, heavy) and disposition (bulk vs. combat configured).

Ship-to-shore connectors. Army forces will need surface and vertical connectors to move forces ashore. Army helicopters are already capable of operating from the sea, albeit with increased maintenance costs. Army watercraft can augment Navy and USMC surface connectors. Army and Navy modular causeway systems can be used to transfer equipment from large vessels to surface connectors. In later phases of the operation, joint-logistics-over-the-shore operations will allow large ships to unload directly onto expeditionary piers.

Importantly, Army forces afloat must be able to move ashore even as the enemy contests this movement across all domains. The Army participants must not count on an uncontested “administrative” offload. Army forces reinforcing a marine amphibious assault, for example, should not expect a large, completely secure lodgment. As previously noted, combat configured units are essential so units can fight immediately or soon after moving ashore.

Joint integration. The operations envisioned here require true joint force integration rather than simple coordination or deconfliction, both technologically and from a command and control perspective. With multiple services operating across all domains, all units must be able to communicate with each other and maintain situational awareness using a common operating picture. While joint communications challenges are not new, they take on additional urgency in this environment.

Joint command will be more challenging in this fight. The joint force maritime component commander (JFMCC) will likely control the counter-anti-access fight. The JFMCC must determine how Army forces will integrate into a predominately naval force, including the command relationships of Army forces, if and how they report to the amphibious task force commander, and when control of land forces shifts to the joint force land component commander. Army forces will be challenged as well. In many cases, Army units could be reporting directly to non‐Army commands. For example, an Army Stryker battalion could be working under a marine brigade, which is in turn working for the JFMCC. The mission command, interoperability, and sustainment challenges of this situation are evident.

Preventing a Mighty Fall

In his 2009 book How the Mighty Fall and Why Some Companies Never Give In, Jim Collins examines why many highly successful companies suddenly fail. The path to failure begins with successes, which lead to an organizational sense of invulnerability. Companies then fail to adapt, and instead try to replicate past success. As failure approaches, companies begin to take excessive risks, followed by desperate grasping at ill-conceived “silver bullet” strategies. Finally, they die or fade into irrelevance.36

The Army has stood too long on the success of the Gulf War while the world around it has changed dramatically. The question now is, will the Army adapt its capabilities to a new and different operational environment or constrain needed development by attempting to replicate previous successes using the relatively recent past as its main template? The Army must not let the lingering influence of the Cold War and Gulf War prevent a restoration of expeditionary capabilities. American expeditionary land power is rooted in history and flows from the natural strategic imperatives of a maritime nation. Success in the coming counter-anti-access fight depends on coordinated and mutually reinforcing air, sea, and land expeditionary forces. The U.S. Army must be ready to do its share.


    Epigraph. Julian Corbett, Some Principles of Maritime Strategy (London: Longmans, Green, 1918), 12.

      1. Dan Lamothe, “Pentagon Chief Declares North Korea the New Top Threat to U.S. Security,” Washington Post (website), 12 June 2017, accessed 5 January 2018,
      2. Lisa Ferdinando, “Carter Outlines Security Challenges, Warns against Sequestration,” U.S. Department of Defense (DOD) (website), 17 March 2016, accessed 5 January 2018,
      3. For simplicity, I will use the term “anti-access” to describe capabilities and strategies commonly associated with anti-access/area denial (A2/AD).
      4. U.S. Army Training and Doctrine Command (TRADOC) Pamphlet (TP) 525-3-1, The U.S. Army Operating Concept: Win in a Complex World, 2020-2040 (Fort Eustis, VA: TRADOC, 31 October 2014), 17.
      5. Winston S. Churchill, “Coal and War” (speech, London, UK, October 31, 1942) in The End of the Beginning (Winston Churchill War Speeches Collection Book 3) (New York: RosettaBooks, 2013), Kindle.
      6. Office of the Under Secretary of Defense for Acquisition, Technology, and Logistics (OUSD[AT&L]), “Defense Science Board Task Force on Seabasing” (report, Washington, DC: DOD, August 2003), iii, accessed 5 January 2018,
      7. Bruce A. Elleman and S. C. M. Paine, introduction to Naval Power and Expeditionary Warfare: Peripheral Campaigns and New Theatres of Naval Warfare (New York: Routledge, 2011), 1.
      8. John B. Hattendorf, foreword to Naval Power and Expeditionary Warfare.
      9. Robert K. Sutcliffe, British Expeditionary Warfare and the Defeat of Napoleon, 1793-1815 (Woodbridge, UK: Boydell Press, 2016), 10.
      10. Michael Duffy, “Festering the Spanish Ulcer: The Royal Navy and the Peninsular War, 1808-1814,” in Naval Power and Expeditionary Warfare, 27.
      11. OUSD(AT&L), “Defense Science Board Task Force on Seabasing,” iii.
      12. Nathan A. Jennings, “Expeditionary Land Power Lessons from the Mexican-American War,” Military Review 97, no. 1 (January-February 2017): 45, accessed 9 January 2018,
      13. Sam Tangredi, Anti-Access Warfare: Countering A2/AD Strategies (Annapolis, MD: Naval Institute Press, 2013), 149.
      14. Robert O. Work, Thinking about Seabasing: All Ahead, Slow (Washington, DC: Center for Strategic and Budgetary Assessment 2006), 14.
      15. Toward an Expeditionary Army: New Options for Combatant Commanders, Hearing Before the House of Representatives Comm. on Armed Services, 108th Cong. (24 March 2004) (testimony of Eric Peltz), accessed 9 January 2018,
      16. Work, Thinking about Seabasing, 14–16.
      17. Edward Luttwack, Strategy: The Logic of War and Peace (Cambridge, MA: Harvard University Press, 2003), 19.
      18. United States Central Command (USCENTCOM), Operation Desert Shield/Desert Storm: Executive Summary (Washington, DC: USCENTCOM, 11 July 1991), accessed 9 January 2018,
      19. Andy Grove, former Intel chief executive officer, defines a strategic inflection point as a time when the fundamentals of a business are about to change. Andrew Grove, Only the Paranoid Survive: How to Exploit the Crisis Points that Challenge Every Company (New York: Currency Doubleday, 1999), 3.
      20. “Operation Desert Storm: Transportation and Distribution of Equipment and Supplies in Southwest Asia,” Report to the Chairman, Subcommittee on Oversight of Government Management, Committee on Governmental Affairs, U.S. Senate (Washington, DC: U.S. Government Accounting Office, December 1991), accessed 9 January 2018,
      21. Work, Thinking about Seabasing, 22.
      22. Tangredi, Anti-Access Warfare, 28.
      23. Ibid., 31.
      24. Steven Metz and James Kievit, Strategy and the Revolution in Military Affairs: From Theory to Policy (Carlisle Barracks, PA: U.S. Army War College, 27 June 1995), v, accessed 9 January 2018,
      25. Dean Cheng, “Countering China’s A2/AD Challenge,” The National Interest (website), 20 September 2013, accessed 9 January 2018,
      26. Tangredi, Anti-Access Warfare, 163; Mike Pietrucha, “Avoiding the Charge of the Light Brigade against China,” War on the Rocks (website), 15 June 2016, accessed 9 January 2018,
      27. Although there is no standard depth to be considered a “deepwater” port, the most common understanding is a port which can accommodate a draft of at least 39.5 feet. This depth will accommodate all Military Sealift Command (MSC) ships.
      28. Anti-access is not the only threat to port access. In some areas the United States may not have allies willing to allow access (Turkey’s refusal in 2003 stands out as an example). In other areas, particularly the western Pacific, there are vast areas without adequate infrastructure to accommodate large ships.
      29. This is not implying the Army should conduct amphibious assaults. However, it must be able to rapidly reinforce U.S. Marine Corps (USMC) amphibious operations, and/or move ashore over a beachhead, which, while not actively contested, is not secured; only sealift can move a combination of light, medium, and heavy forces at sufficient scale and speed to an expeditionary fight. Heavy airlift cannot move a sufficient volume to build, on its own, a significant land force. I refer the reader to the following study: Alan J. Vick, David T. Orletsky, Bruce R. Pirnie, and Seth G. Jones, The Stryker Brigade Combat Team: Rethinking Strategic Responsiveness and Assessing Deployment Options (Santa Monica, CA: RAND Corporation, 2002), 23.
      30. TP 525-3-1, The U.S. Army Operating Concept, 17.
      31. Additionally, the Navy is likely to be the Army’s primary provider of joint fires in the absence of usable bases for Air Force aircraft.
      32. “US Ship Force Levels: 1886-Present,” Naval History and Heritage Command (website), accessed 9 January 2018,; “Navy Demographics as of January 19, 2017,” U.S. Navy (website), accessed 9 January 2018,
      33. “The Question: How Many Ships?,” USMC (website), accessed 9 January 2018,
      34. Hope Hodge Seck, “In Innovation Push, Navy Brass Look to Repurpose Seabasing Vessels,” Defense Tech (website), 4 April 2017, accessed 9 January 2018,
      35. John W. Nicholson, “NATO’s Land Forces Strength and Speed Matter,” Prism 6, no. 2 (2016): 40.
      36. Jim Collins, “How the Mighty Fall and Why Some Companies Never Give In,” Cleveland Consulting Group (website), 2009, accessed 9 January 2018,


      Lt. Col. Trent Lythgoe, U.S. Army, is an aviation officer serving as an instructor at the U.S. Army Command and General Staff College, Fort Leavenworth, Kansas. He holds a BA from Weber State University and an MA from Webster University. Lythgoe’s previous assignments include the Army Capabilities Integration Center, 3rd Infantry Division, 25th Infantry Division, Eighth U.S. Army, and 1st Cavalry Division.

March-April 2018