The Law of War and You

Not Just for Academics, Eggheads, and JAGs Pt. 2

By MAJ Jonathon Krisko

June 24, 2026 | Field Artillery, 2026 E-Edition

Read Time: < 15 mins

U.S. Army 2nd Lt. Benjamin Campbell (right), a fire support officer assigned to 3rd Battalion, 7th Field Artillery Regiment, DIVARTY, 25th Infantry Division, assists Philippine Army partners in using a U.S. Army Laser Target Locator Module to observe artillery fire impacts at Laur, Nueva Ecija, Philippines, April 16, 2026. Salaknib is an annual exercise designed to enhance interoperability and strengthen relationships between partner nations. (U.S. Army photo by Pfc. Peter Bannister)

This article is part two of a two-part series about how fires officers must master law-of-war decision making. Please make sure to read part one for the full overview.

The GWOT Era, a Push for Change from the Top, and Emerging Policy Changes

While the GWOT ROEs may have been a reasonable response to the battlefield and political situations of a 21st-century complex counterinsurgency, the application and reinforcement of such rules shaped the mindset of an entire generation of service members. Seeing this danger, a cross-service movement has been underway across all echelons to shake off the “lingering hangover of constrained COIN ROE” and the hesitancy and risk aversion that may accompany it.¹ In 2021, LTG Charles Pede, then serving as the Army’s judge advocate general, and COL Peter Hayden identified “legal maneuver space” as “The Eighteenth Gap” facing a U.S. Army that would eventually be called upon to fight an LSCO after decades of policy-restricted counterinsurgency. They sought to highlight the differences between the ROE and the law of war and show the risks associated with excessive legal caution during the next major fight, such as commanders hesitating or under-utilizing the lethal tools available. By articulating how commanders and their lawyers share a burden for knowing the law and being able to cut through the noise created by legal “influencers,” such as non-governmental organizations (NGOs) and aid organizations that may be present in theater, they provided a call to action for military lawyers. Those JAGs must take a proactive role in the legal education of their supported formations and provide clear, mission-oriented counsel that does not unduly restrict the lethality of their formations.²

The military-internal call for preparing the legal landscape for LSCO was significantly amplified in early 2025 with the publication of “Lethal Force, Risk, and LSCO: Preparing for Permissive Rules of Engagement in Large-Scale Combat Operations.” Written by LTG Milford Beagle Jr. (Commander, Combined Arms Center), LTG Joseph Berger III (the Judge Advocate General of the Army) and LTC Jack Einhorn, it exemplified the close coordination that should regularly occur between maneuver-oriented commanders and their JAGs when developing strategies to maximize effectiveness on “battlefield next.” To move away from the ingrained culture of restraint that has pervaded across the force, which may serve to hinder rapid and decisive decision making, subordinates must be empowered through both education and training. Doing so repeatedly and as realistically as possible in training environments will allow lower-level combat formations to display initiative and apply lethal force decisively when and where needed.³

These hard-hitting pieces, each co-authored by the then top-Army lawyer, have primed military leaders for the policy change that is now in progress. With the GWOT becoming established history (as evidenced by its inclusion in the Command and General Staff College’s history curriculum), the Department of Defense is now postured to fight a war with significantly fewer internal-policy constraints. However, military lawyers and political appointees are not tactical decision makers, nor are they generally trigger-pullers in all but the most extreme circumstances. The actual work to see this policy shift turn into real-world battlefield effects must be done by fires and maneuver officers who can understand and apply the new policies to the next battlefield on the fly.

From Cushion to Consequence: Navigating Narrowed Margins Between Policy and Law

While a less-restrictive ROE may make it easier to employ lethal effects in populated areas, it significantly increases the stakes of making the correct call with the information available. In contrast, the GWOT era ROEs often provided a considerable amount of cushion between what was prohibited by the ROE and what was forbidden by international law. You could theoretically violate a more restrictive ROE—with requirements for direct observation, mandatory pre-strike assessments of expected civilian casualties, and highly restrictive no-strike lists—and still be miles away from an actual violation of the law of war. However, when the ROE and law of war significantly overlap, that cushion is markedly reduced, and any significant deviation from the ROE is more likely to be a law-of-war violation.

Fortunately, the law of war recognizes that nations (and others) will engage in bloody and destructive conflict. Soldiers across the spectrum must assess the military necessity of any action (and therefore determine how that necessity interacts with proportionality) with the information available to them, not a then-unknown truth that later comes to light.⁴ Thus, the laws are sufficiently clear, practical and permissive enough to be followed in practice and allow the accomplishment of militarily necessary tasks, even if they might come at the cost of some innocent life. The law of war also requires warriors to be intimately involved in its study, discourse and application. Your friendly neighborhood JAG is likely well-informed but, like many specialty MOSs and those who sit on brigade or higher staffs, may not have the same intimate knowledge of the battlefield, capabilities and drawbacks as those officers who must directly employ violence to achieve success.

That is not to say there will not be restrictions placed on our activities, and leaders must be ready to adapt even in the most serious LSCO environments. After all, we are the good guys and have historically moderated some of our capabilities when appropriate for preserving civilian life. As an expeditionary Army often fighting for the liberation of others, one of the key reasons for this is that we will be fighting in the cities of our partners or allies. One of the nastiest city-fights of World War II, the Battle of Manila, had an ROE that prohibited air strikes and restricted artillery fire to observed pinpoint targets within the city in a bid to lessen the destruction wrought upon the enormous civilian population trapped within.⁵ While not necessary under the law of war, these restrictions struck a balance between preserving additional innocent life (in this case, U.S. nationals) and ensuring enough combat power was available to root out a determined enemy.⁶ Particularly with friendly civilians, we do not want to “destroy the town to save it.”⁷ But even fighting the bitterest of foes, there may be good reasons to take additional steps to protect civilians. In the grinding Battle of Aachen in October 1944, U.S. forces systematically evacuated all the civilians it encountered from the rubbled city.⁸ While this served a humanitarian purpose, safeguarding them from the fight, it also provided military benefits by preventing interference, intelligence gathering, or possible partisan attack from areas cleared of uniformed enemy troops.⁹

War as It Is, Not as We Wish It to Be

Emerging U.S. policy, paired with our historically more aggressive view of the law of war, is the most appropriate for the large-scale urban options we will eventually face. While commanders may want to avoid bogging down their exquisite maneuver-centric forces in a grinding urban fight, cities will need to be captured not only because of their geographic importance but also because of their position as centers of leadership, economics, culture and enemy will. Accordingly, fires officers must be prepared to support the urban fight and to do so with the broad range of their capabilities. The ubiquity of precision warfare seen in the GWOT is an aberration. As the U.S. presently has difficulty manufacturing even enough conventional artillery projectiles to support the conflicts in Ukraine and Gaza (while maintaining our own stockpile), the inventories of more complicated and expensive PGMs will deplete quickly unless they are withheld for specialized missions.¹⁰ For instance, during the 2016 to 2017 Battle for Mosul, a reliance on PGMs dramatically cut into America’s stockpile of precision weapons, with coalition forces almost running out of them by the end of the battle.¹¹ If such a shortage was primarily generated by a single city fight as part of a non-LSCO campaign against ISIS, it does not take much to imagine what a continent-spanning fight against a near-peer adversary would do to existing stockpiles.

Even if the U.S. could ramp up production of purpose-made PGMs and supplement them with screw-on precision guidance kits, they would likely need to be rationed for key missions while conventional projectiles remained the norm. Additionally, such high-tech weapons are subject to the continual cat-and-mouse game of technological advancement currently experienced in Ukraine, where both sides seek to negate their adversary’s technological advantage.¹² While PGMs can be an exceptional tool, the concept of precision itself is subjective, and the pendulum has swung too far from WWII to the present. Despite claims from NGOs that unguided tube artillery is inherently indiscriminate and should, therefore, be prohibited in populated areas, the ability of U.S.-produced and crewed artillery to put unguided rounds on target is genuinely phenomenal. While it may not be 10-digit-grid exact, our fire supporters and their protocols are the best in the world.

Not only will U.S. forces benefit from the traditional law-of-war approach but so may civilian populations. There is a perverse incentive for defenders (particularly non-state or rogue states) to dig in and bitterly contest cities if they believe the attacker will follow restrictive guidelines on explosive use as proposed by international humanitarian organizations such as the International Committee of the Red Cross.¹³ Should an attacker choose to comply with the more restrictive strain of thought regarding city-fighting, they would be required to stockpile vast amounts of low-yield PGMs (attainable for only the wealthiest nations) and prepare for bitter street-by-street fighting against an enemy with largely intact defensive positions. While this will undoubtedly result in more casualties for the attacking ground force, it is naïve to assume that civilian casualties or damage will be markedly less when each block and building is contested. While our approach to the law of war will not likely dissuade an enemy determined to hold a city, it will at least not grant them significant advantages.

Finally, the surgical precision of PGMs may not be as effective at eliminating threats and limiting collateral damage as claimed. Analysis of the Battle of Mosul notes that precision strikes on targets generally did not kill all enemy fighters present, causing the survivors to disperse into the surrounding urban terrain and requiring follow-up strikes. Not only did PGMs fail to eliminate threats decisively, allowing the remaining enemy the ability to continue combat operations, but subsequent precision strikes, now necessary to kill the dispersed enemy forces, resulted in more damage to civilian structures and the loss of civilian life. Accordingly, MAJ Amos Fox writing for the Association of the United States Army (AUSA) asserts, “This cause-and-effect loop, or Precision Paradox, creates a situation in which the failed promise of precision strike—one strike, one kill—generates a creeping wave of destruction across the battlefield.”¹⁴

Being Right Is Not Enough; We Need to Be Better

Traditionally applying the existing principles is sufficient from a conceptual standpoint for a fight over an urban center. We will not deliberately target civilians, we will identify targets whose destruction is a military necessity and we will weigh that military advantage to be gained against the expected civilian damage. All of this is undergirded by the concepts of humanity and honor, which are ingrained into our military culture. However, from a practical standpoint, much work must be done to create a combat force that can analyze battlefield information quickly and make accurate legal determinations under the law of war when far from their supporting JAG. What the current fires officer, across all ranks, can do today to help better prepare themselves is read, reach out and re-train.

Read

The first suggestion is the simplest: You need to read the law, specifically the “Department of Defense Law of War Manual,” updated in July 2023. This blue-bound tome is readily available online and is the definitive source on how the U.S. interprets and applies international law. More importantly, it is not written in the archaic language of lawyers but in plain language with helpful explanations for the educated warfighter. Just as the law of war needs to be simple enough to be followed by combatants, the DoD wisely decided that its manual must be easy to comprehend. And while it is all very important information, you can make the task much less daunting by honing in on the provisions that would have the broadest applicability in the early stages of the next LSCO. While tactical approaches to reading this can vary (such as reading one bite-sized sub-section daily), the fundamental truth remains: You need to read it.

Reach Out

In addition to personal study, communicate with your brigade judge advocate or other uniformed legal advisor. Not only will you find a fellow officer likely to enjoy discussing the finer points of the law of war, but you can also get help establishing a training class or program tailored to your unit or staff section. The JAG Corps has created generalized support packages for the law of war, which are a solid start. However, the fires community in particular has a diverse need for specialized instruction, running the gamut from the PV2 Forward Observer to the O-6 Corps Fire Support Coordinator. By making such connections with your JAGs, you can wring the most value from them when and where it counts—at home station and well before any battle. However, this action must be a conscious decision since, under the recently revised “FM 350-1” effective June 2025, law-of-war training is no longer mandatory.¹⁵ This can be turned into an advantage by the shrewd leader, who can now help create a more personalized class instead of what was too often a mass check-the-block briefing. By contacting your JAG, you will make a valuable connection if the need for battlefield legal advice arises and the situation permits such deliberation. And if there is no JAG or no time on that future battlefield, you and your soldiers will at least have a solid educational basis to fall back on.

Re-Train (and Train, and Train, and Train)

Despite the unquestionable value of a beautifully crafted PowerPoint presentation, commanders and leaders need training on the law of war that goes beyond slide decks and canned vignettes. Law-of-war issues should be worked into home-station warfighters and CTC rotations to test JAGs, commanders, targeting cells and the staff—both as a system and individual entities—who must rely on their own understanding and experience. Instead of dreading the “legal inject,” units should view it as another chance to demonstrate mastery of something that reflects their professional status. Such shakedowns will also test key warfighting products, such as the target authorities matrix, and ensure that all levels understand how to utilize them in the heat of battle. As with classroom instruction, the time to begin training in this decision making is not in the immediate train-up for a deployment or during the plane ride towards a contingency response. Instead, these must be deliberately worked into training by JAGs and planners alike to ensure that they provide realistic training scenarios in a forgiving environment. When the time comes, commanders and their staff cannot be afraid to yank the lanyard and must be secure in their training and application of the law of war.

Conclusion

No one can predict precisely what the next war will bring, but the likelihood of LSCOs encompassing expansive urban areas is too high to ignore or hand-wave. Given their unique tasks and training, fires officers must be the preeminent non-JAG experts on the law of war. This journey must start now so that the Army is prepared for whatever the future holds, especially if it is one where commanders do not have immediate access to JAGs. By decentralizing a working knowledge of the law of war, we can more quickly and violently apply our entire arsenal of capabilities while respecting the law.

Fires officers at all echelons must make split-second decisions with incomplete information in highly complex environments. These decisions will have profound tactical, operational, and strategic implications, not only affecting the immediate battlefield outcome but potentially impacting the nation’s international standing, coalition partnerships and the overall narrative of the conflict. While JAGs will continue to provide essential legal expertise, the reality of modern combat requires combat-arms officers who can independently analyze and apply the law-of-war principles across the full spectrum of operations. This is especially true for fires officers who must deliver devastating effects while balancing military necessity against often unavoidable collateral damage. The artillery community’s ability to strike this balance—to deliver maximum lethality while remaining within legal boundaries—will be a decisive factor in future conflicts.

The path forward is clear but demanding. It requires a cultural shift away from the risk-averse mindset cultivated during two decades of COIN. It demands honest self-education through the study of the “Department of Defense Law of War Manual.” It necessitates proactive collaboration with legal advisors during peacetime to develop tailored training programs. Most importantly, it requires realistic, challenging training scenarios that integrate law-of-war considerations into multiple aspects of planning and execution. As we prepare for the next conflict, we must remember that the law of war is not an impediment to effective operations but a framework that allows warfighters to employ maximum force against legitimate military targets while maintaining our nation’s moral authority. By embracing this understanding and committing to the hard work of education and training, fires officers can ensure that U.S. artillery remains what it has always been: a decisive element of American combat power that can be unleashed with confidence against our nation’s enemies.

Thank you for reading part two of this two-part series.

References