Prepare the Marine Corps for a Protracted War

The opening days of the war in the Pacific were as brutal as forecast. Electronic attacks and cyber operations blinded command centres and sowed confusion. Precision munitions rained down on bases and stations. Surface combatants fought briefly before missile strikes sent them to the bottom of the sea. Aircraft flew through storms of steel and were shot down after a single sortie.

US Marines and sailors conduct a jungle endurance test at the Jungle Warfare Training Center in Okinawa, Japan. The next fight in the Pacific will be long and brutal, and the Marine Corps must have adequate numbers trained and ready to deploy to replace fallen members. US Marine Corps (Joaquin Dela Torre)

As part of the stand-in force (SIF), III Marine Expeditionary Force (MEF) dispersed to expeditionary advanced bases across the first island chain. They fought as trained – shooting judiciously, moving constantly, and communicating when able. But attrition took its toll, and reinforcement was desperately needed. I MEF deployed across the Pacific as soon as possible to prevent the SIF from collapsing, falling in on III MEF positions. In turn, II MEF pushed forward to take up the previously assigned mission of I MEF, with Marine Forces Reserve (MarForRes) activating and assuming the former roles of II MEF. Within 30 days, the entire Fleet Marine Force and its reserves were committed to the fight.

But the war continued, and Marines continued to die. New forces were needed, but the same leaders and teams necessary to stand up new formations were already deployed. It became apparent that the war could last for years, yet the Marine Corps had sacrificed the seed corn for new battalions and squadrons on the bloody beaches of the Pacific. The Service could regenerate, but at a much slower rate and a much steeper cost than policymakers needed to maintain the initiative.

This vignette depicts a possible fate for US Marine Corps forces in the next Pacific war. Wargames and forecasts of how this conflict could play out vary, but they generally agree on one thing: It will be destructive and the cost in lives of US Service Members will be significant. For the Marine Corps, there is one reasonable conclusion in this case: The SIF will, eventually, succumb to the same attrition.[1] In the context of a fight with China, based on the analysis of the forces that will be within the first island chain when the fighting starts, this could be the initial fate of III MEF.

Marine Corps recruits recite the oath of enlistment at Recruit Depot Parris Island on 19 April 2025. Reinstitution of the draft may be required to maintain the forces necessary in a brutal and protracted war. US Marine Corps (William Horsley)

This is not a criticism of the SIF as a warfighting concept, nor of the readiness or lethality of III MEF as a core element of the SIF. These forces are critical to deterring China, as III MEF can put credible forces in the right place at the right time – in theatre and positioned to foil Chinese war plans before the shooting starts. Rather, this is an observation of the effects of time, space, and force in relation to the combat power of the People’s Liberation Army (PLA) compared with that of US and coalition forces within the first island chain.

The first island chain is China’s backyard – its forces will enjoy the advantage of interior lines of communication, have greater operational reach, and have greater depth in force in all domains relative to US and friendly forces. In the opening phases of such a fight, prudent planners should assume III MEF will be targeted and degraded significantly enough to require immediate relief and reinforcement from I MEF, II MEF, and MarForRes, whether such was previously planned.

In addition, it is unlikely such a war would be short and sharp. Wars between great powers tend to be years-long slogs of attrition.[2] The immediate cause of the war usually is not why the war continues. The objective often shifts from a key piece of terrain to the world order that will exist after war’s end. Offramps are not taken when the fates of societies are at stake. A war for Taiwan, for example, could quickly become a war for the Pacific and, in turn, a war for whose interests will reign when the war grinds to a close.[3]

For the Marine Corps, this means many of its forces would be destroyed, formations would need to be reconstituted, and the service likely would need to expand significantly. The same pattern witnessed in both world wars would necessarily repeat itself.

The difference in a new war in the Pacific – specifically, in a great power war with China – is that Beijing’s precision-strike regime would result in greater losses at a faster rate. These losses would create a new sense of urgency to get existing forces into the fight to prevent the collapse of the first island chain and Taiwan, and then perhaps the fall of Okinawa, northern Luzon, and other objectives of opportunity for China. In turn, this would reduce the time available to stand up new formations such that they are operationally relevant to this first phase of a years-long war. The focus for planners and leaders will be supporting the fight of the moment, and they will be hard pressed to plan for the years of fighting yet to come.

To be ready for this, the Marine Corps must commit to planning not just how to fight now, but also how to rapidly regenerate and expand to fight for the long term. Approaches used during World War II offer valuable lessons, but these must be recontextualised to account for changes in modern warfighting, changes in US society, and the compressed military pressure to get forces into the fight as soon as possible. The Marine Corps must account for the cadres needed to regenerate the forces that will be lost and the resources needed to expand training facilities and training cadres to grow the force to the size required to finish the fight.[4]

If the Marine Corps does not commit to this plan now, it risks expending its resources in the opening phase of the next war in the Pacific.

Marines fire an M252 81-mm mortar system during an exercise in Thailand on 6 March 2026. The Marine Corps must explore options and develop new bases with spaces for a range of training operations. US Marine Corps (Shania Jupiter)

Look Back to Look Forward

World War II abounds with lessons for preparing for protracted war. At that time, the Marine Corps rapidly expanded by orders of magnitude; the Service quickly integrated draftees, grew basing and training centers, and learned to reconstitute corps- and division-sized formations after experiencing attrition in brutal fighting across the Pacific. An analysis of these issues provides takeaways for future planning.

• Expanding the force. Prior to its entry into World War II, the United States was already expanding its military forces in anticipation of being drawn into the conflict. In June 1939, before Germany’s invasion of Poland, the Marine Corps consisted of slightly more than 19,000 members. After France was invaded in May 1940, US military expansion accelerated, and the Service grew to more than 65,000 Marines by November 1941, just prior to the attack on Pearl Harbor. This included the full mobilisation of the Marine Corps Reserve.

This enabled the Marine Corps’ two brigades to grow into divisions and provided for the development of two air wings. Commissioned and noncommissioned officers were pulled from formations across the Marine Corps to serve as training cadres around which to build these units. However, even building on experienced cadres, it took months for these divisions to grow to their authorised strengths.[5] Notably, it took this long without direct military pressure.

The Marine Corps must conduct rigorous analyses of the forces needed to fight and win a long war in the first island chain. The cadre needed to train these forces should be identified so the service will be prepared to detach them from parent organisations. Likely, this will mean carving forces from the Fleet Marine Force, assuming risk on behalf of operational commanders. This risk must be conveyed to the commanders who will lose manpower to build these cadres. Finally, commanders must be prepared to send some of their best leaders to serve on these cadres. Giving up Marines to build quality cadres should hurt the command, at least a little bit, or the formations they will grow will lack quality in turn.

• Integrating the draft. During a protracted war, a draft could be necessary to raise and maintain forces to authorised end strengths. During World War II, approximately 39% of US Service Members were volunteers, while the majority were conscripted.[6]

Marine Corps planners should assume a similar breakdown of the volunteer-to-draftee ratio would occur. For this reason, planners must account for societal changes that continue to affect recruiting and retention. Many draftees initially may not meet physical or academic qualifications for service, but this could be mitigated through proactive, upstream approaches such as the US Army’s pre–basic training courses.[7] In addition, medical conditions and minor drug-use infractions that previously were disqualifying should be waived, excepted, or removed from policy. Failure to do so could hinder the Marine Corps’ efforts to grow quickly at a critical time.[8]

• Expanding bases and training centers. The influx of new military recruits – even before the United States entered World War II – brought recruit depots at Parris Island and San Diego to maximum capacity. Further, the development of two divisions and wings flooded available Fleet Marine Force basing. This led to the activation of Camp Elliot on the West Coast and, through congressional approval and funding, the establishment of Tent Camp #1, Marine Barracks, New River, on the East Coast. Still, it took months for this camp to become a fully functional base as it grew into what would become one of the Marine Corps’ largest installations, Camp Lejeune.[9]

As World War II progressed and the Allies regained territory in the Pacific, Marine Corps camps and training centres were developed closer to the fight, such as Camp MacKay in New Zealand. Forward basing and shorter lines of communication vis-à-vis ‘the front’ would remain vital in a protracted war.

The Marine Corps must explore options for rapidly expanding current bases as well as developing new bases in locations with permissive space for the full range of training operations. Further, plans for forward basing closer to the first island chain must be developed.

• Reconstituting the force. While fighting at Guadalcanal, the 1^st Marine Division endured enough losses that it was rendered ineffective. From integrating combat replacements to healing its walking wounded and conducting sustainment training in basic military skills, it took approximately six months for this division to reconstitute as an effective fighting force.[10] Similar timelines for reconstitution will apply to corps- and division-sized units across the Pacific.

It could take half a year or longer to reconstitute III MEF and 3^rd Marine Division after the opening phases of a fight against China. Timely reinforcement from the rest of the Fleet Marine Force, and plans to regenerate MEFs and divisions, must be anticipated in planning.

Marines with III Marine Expeditionary Force (MEF) perform tactical combat casualty care techniques during a training exercise to expand readiness. It could take six months or longer to reconstitute III MEF in a war with China, and plans to regenerate the force must be part of planning. US Marine Corps (Meshaq Hylton) 

Prepare to Fight a Protracted War

Overall, the Marine Corps’ rapid expansion and adaptation during World War II were essential for its successful contribution to the Allied victory. A war against China would be similar in its scale of destruction. By analysing the hard-won lessons of its previous participation in total war, the Marine Corps can plan now.

Leading Marine Corps thinkers cannot focus only on the close, near fight, but also must plan for the campaigns that could follow across a protracted war. By planning for challenges in a war with China similar to those it faced in the war with Japan, the Marine Corps will be postured to fight not just in the war’s opening phases, but also through the war’s end.

This article originally appeared in the U.S. Naval Institute Proceedings. Copyright U.S. Naval Institute. Reprinted with permission. For more great content from the U.S. Naval Institute, visit www.usni.org.

References

[1] Mark Cancian, Matthew Cancian, and Eric Heginbotham, The First Battle of the Next War: Wargaming a Chinese Invasion of Taiwan (Washington, DC: Center for Strategic and International Studies, 9 January 2023), 130.

[2] Ryan Easterday, ‘The Fallacy of the Short Sharp War,’ The Strategy Bridge, 16 March 2023.

[3] Lt Col Brian Kerg, USMC, ‘There Will Be No ‘Short, Sharp’ War. A Fight Between the U.S. and China Would Likely Go on for Years,’ New Atlanticist, 19 March 2024.

[4] Iskander Rehman, Planning for Protraction (London: Routledge, 2023), 4–15.

[5] Frank Hough, Verle Ludwig, and Henry Shaw, History of U.S. Marine Corps Operations in World War II, vol. 1, Pearl Harbor to Guadalcanal (Washington, DC: History Division, Headquarters U.S. Marine Corps, 1958), 47–48.

[6] The National World War II Museum, ‘Training the American GI,’ www.nationalww2museum.org/war/articles/training-american-gi.

[7] Steve Beynon, ‘Once a Pilot, Army Program for Recruits Who Fall Short of Weight, Academic Standards Is Becoming Permanent,’ Military Times, 30 August 2023.

[8] Cdr Brian Sattler, USCG, ‘Recruit Medical Standards Are Out of Touch,’ < https://www.usni.org/magazines/proceedings/2024/march/recruit-medical-standards-are-out-touch > U.S. Naval Institute Proceedings 150, no. 3 (March 2024).

[9] Hough, Ludwig, and Shaw, History of U.S. Marine Corps Operations in World War II, 52.

[10] Stephen Taafe, Commanding the Pacific: Marine Corps Generals in World War II (Annapolis, MD: Naval Institute Press, 2021), 61. < https://www.usni.org/press/books/commanding-pacific >