How International Humanitarian Law Encodes Shared Human Value

The battle of Solferino was fought on 24 June 1859 in northern Italy. On one side, the Franco-Sardinian alliance under Napoleon III. On the other, the Austrian Empire under the young emperor Franz Joseph. It was the last major battle in European history commanded in person by reigning sovereigns on both sides. About 300,000 soldiers fought over a single summer day. By nightfall, between 35,000 and 40,000 were dead, wounded, or missing.

The medical infrastructure was catastrophic. There were only four veterinary surgeons per horse regiment, not more than a handful of army doctors per infantry brigade. The wounded were spread across kilometers of fields. Summer heat reached 38 degrees Celsius. Local villages were overwhelmed. For three days, the battlefield was a slow dying ground.

Henri Dunant, a Swiss businessman traveling to meet Napoleon III on an unrelated matter, arrived that evening. He stayed a week. What he saw — and above all what he did, organizing village women to carry water and tear sheets into bandages for men regardless of uniform — became the origin point of the Red Cross.

His book Un Souvenir de Solferino, published 1862, self-funded, sent to monarchs, parliamentarians, generals across Europe, made two proposals.

One: "in time of peace and quiet, to form relief societies for the purpose of having care given to the wounded in war time by zealous, devoted and thoroughly qualified volunteers."

Two: an international convention to guarantee the neutrality of military medical services.

The first produced the International Committee of the Red Cross, founded 1863 in Geneva. The second produced the first Geneva Convention, signed 1864 by 12 states, titled "for the Amelioration of the Condition of the Wounded in Armies in the Field."

The Red Cross itself was a branding innovation. The symbol — a red cross on a white field, the Swiss flag inverted — was chosen to be recognizable from distance on a battlefield. In 1929 the red crescent was added. Later still, the red crystal.

It is worth pausing on the scale of the move. Before 1864, the wounded soldiers of an army were the responsibility of that army's medical service, and if that service failed — which it usually did at scale — they died. The enemy's medical service had no obligation to them and often could not tend to them without risking attack. What the Geneva Convention did was carve out a category of persons and functions that belonged to all sides and to none: the neutral medical worker, the protected field hospital, the wounded as non-combatant.

This carving is the elementary particle of IHL. Everything else grows from it.

The treaty body grew in fits.

1864. First Geneva Convention. Wounded soldiers in field armies.

1899 and 1907. The Hague Conventions. Rules on declaration of war, means and methods of warfare, treatment of prisoners, conduct of occupation, prohibition of specific weapons (dum-dum bullets, poison, balloons dropping projectiles).

1925. Geneva Protocol prohibiting chemical and biological weapons. A direct response to the chlorine and mustard gas horrors of World War I.

1929. Updated Geneva Conventions, now explicitly protecting POWs.

1945–1948. The Nuremberg trials and the Tokyo trials. The London Charter of 1945 defined war crimes, crimes against humanity, crimes against peace. Leaders were tried, not soldiers following orders. The defense of "superior orders" was rejected. New law was written in real time, and applied retroactively — an uncomfortable but transformative precedent.

1948. The Universal Declaration of Human Rights. The Genocide Convention.

1949. The four Geneva Conventions, in one comprehensive body: - GC I: Wounded and sick in armed forces in the field. - GC II: Wounded, sick, and shipwrecked members of armed forces at sea. - GC III: Prisoners of war. - GC IV: Civilians in time of war.

This was the moment IHL became civilian-inclusive. The protection of civilians in occupied territory, in internment, in siege, in bombardment, got its first serious treaty framework. This happened after WWII, after the firebombing of European and Japanese cities, after the Holocaust, after Leningrad. The lessons were burned in.

1977. Additional Protocols I and II. Protocol I: international armed conflicts. Protocol II: non-international armed conflicts — civil wars. This was the recognition that the worst modern violence was no longer state vs state but state vs insurgency, or faction vs faction within a state.

1980–1998. Specific weapons conventions. Cluster munitions. Landmines. Blinding lasers. Incendiary weapons. Each is a small targeted addition to the catalogue of things that cannot be done.

1993. International Criminal Tribunal for the former Yugoslavia (ICTY). The first international criminal tribunal since Nuremberg. Prosecuted war crimes, crimes against humanity, genocide. Indicted 161 individuals. Concluded operations in 2017. Among its achievements: defined rape as a weapon of war, convicted heads of state, established chain-of-command accountability.

1994. International Criminal Tribunal for Rwanda (ICTR). Same model, directed at the 1994 genocide. Indicted 93 individuals, convicted 61 including the former prime minister Jean Kambanda.

1998/2002. The Rome Statute, creating the International Criminal Court (ICC). The first permanent international criminal court. Jurisdiction over genocide, crimes against humanity, war crimes, and the crime of aggression. 124 states parties today. Notable absentees: the United States, Russia, China, India, Israel, many others.

2017. The Crime of Aggression becomes an active ICC jurisdiction — the crime of planning and waging a war of aggression, the core charge at Nuremberg, finally a living international offense again.

Each step is small. The sum is the densest body of law on armed conflict in human history.

IHL rests on four principles that lawyers cite constantly.

1. Distinction. Parties to a conflict must at all times distinguish between combatants and civilians. Attacks may only be directed at combatants and military objectives. Article 48 of Additional Protocol I is its foundational statement.

2. Proportionality. Even when attacking a legitimate military objective, the expected incidental civilian harm must not be excessive in relation to the concrete and direct military advantage anticipated. Article 51(5)(b) of Additional Protocol I.

3. Precaution. Parties must take all feasible precautions in the choice of means and methods of attack to avoid or minimize civilian harm. Article 57 of Additional Protocol I.

4. Humanity. It is prohibited to employ weapons, projectiles, and material and methods of warfare of a nature to cause superfluous injury or unnecessary suffering. Article 35(2) of Additional Protocol I.

To these, some lawyers add necessity — only force necessary to achieve the military objective is permissible. Together, these principles give a structured vocabulary for analyzing every military operation.

Note the word "feasible." IHL does not require impossibility. It requires the best that can reasonably be done. This is a practical compromise. It is also a loophole — "feasible" is contested in every serious case. Most disputes in modern war-crimes analysis come down to proportionality and feasibility judgments.

The common accusation is that IHL is a dead letter — it sounds nice, nobody enforces it. The reality is more textured.

Nuremberg, 1945–46. 24 major Nazi defendants tried. 12 sentenced to death, 7 to imprisonment, 3 acquitted. Subsequent trials under Control Council Law No. 10 convicted many more. Legally transformative: established that individuals — not just states — are criminally liable for war crimes and crimes against humanity; rejected "following orders" as a defense.

Tokyo, 1946–48. 28 Japanese defendants. 7 executed. Criticized heavily for inconsistency (the emperor was not tried) and for "victor's justice." Still, the precedent stood.

ICTY, 1993–2017. 161 indictments. 90 convictions. Notable: Ratko Mladić, convicted of genocide for Srebrenica. Radovan Karadžić, same. Slobodan Milošević, died during trial. Established chain-of-command liability for failure to prevent or punish subordinates' crimes.

ICTR, 1994–2015. 93 indictments. 61 convictions. Jean Kambanda, former prime minister of Rwanda, pleaded guilty to genocide and is serving life. Established that media figures can be prosecuted for incitement to genocide (Ferdinand Nahimana, Jean-Bosco Barayagwiza of RTLM).

Special Court for Sierra Leone. Charles Taylor, former president of Liberia, convicted of aiding and abetting war crimes and crimes against humanity. Sentenced to 50 years.

ICC, 2002–present. Slower. More contested. Jurisdiction limited to states parties or UN Security Council referrals. Convictions include Thomas Lubanga, Germain Katanga, Ahmad al-Mahdi (destruction of cultural heritage in Mali), Bosco Ntaganda, Dominic Ongwen. Arrest warrants issued against sitting heads of state — Omar al-Bashir of Sudan, Vladimir Putin of Russia.

Universal jurisdiction prosecutions. Some states — Germany, Sweden, Switzerland, Belgium — prosecute war crimes under universal jurisdiction, regardless of where committed. Germany has prosecuted Syrian regime officials for torture. This is a growing domestic-international overlap.

National prosecutions. Many more than commonly realized. Argentina, Chile, Peru, Guatemala have all prosecuted former officials for atrocity crimes. Post-Balkan states have run extensive domestic war-crimes dockets.

Truth commissions. Not prosecutions but accountability mechanisms. South Africa's TRC. Peru. Sierra Leone. Timor-Leste. Canada (residential schools). Colombia. These are IHL-adjacent — not punitive but recording-and-testifying mechanisms that establish public record of what happened.

Sanctions and travel bans. Individuals accused of atrocity crimes face asset freezes, travel restrictions, social ostracism in much of the world. Not the same as prosecution but not nothing.

The overall picture is this: the chance that a person who commits a major atrocity crime will face some form of accountability is much higher in 2026 than in 1926. It is still not high enough — most war criminals die peacefully in beds. But it is higher. The ratchet has moved.

It is important to be honest about limits.

It does not prevent war. IHL is not about whether war happens. It is about how war is conducted. Wars start for reasons that have little to do with law.

It does not protect all civilians equally. Power asymmetries determine who is seen as worthy of protection. Civilians in wars covered by major Western media receive different attention than civilians in wars covered less.

It is often violated with impunity. Great powers routinely evade accountability. Permanent members of the UN Security Council have veto power over referrals to the ICC. The world's strongest militaries are frequently not parties to the key protocols.

It creates its own distortions. Some argue that IHL, by legitimizing some kinds of killing (of combatants) while prohibiting others (of civilians), sanitizes war. Others argue that the distinction it draws between combatants and civilians is increasingly unstable in the age of drones, cyberwar, and non-state actors.

Enforcement is political. ICC jurisdiction depends on state cooperation. Arrest warrants against heads of state go unenforced. Tribunals are expensive and slow. Evidence preservation in war zones is difficult. Witnesses are killed.

None of these limitations negate the value of the framework. They specify the frontier at which it still fails.

Why write it down? Why not just appeal to conscience?

Codification creates common knowledge. If there is a written rule that attacking hospitals is illegal, then every soldier, every commander, every state knows that every other knows it. This is common knowledge in the game-theoretic sense. It forecloses the excuse of ignorance. It also makes lying about it expensive, because the audience has the rule book.

Codification constrains leaders. A leader who orders a war crime now knows that, in addition to whatever other consequences, there is a documented category of "crime" that applies. This may not deter the worst leaders. But it raises the cost at the margin.

Codification enables specialization. Once the law exists, a profession can grow around it — lawyers, judges, investigators, monitors, journalists specializing in laws of war. These professions create a network of people whose job is to notice and name violations. This network does not always produce justice. It always produces record.

Codification shifts norms over generations. A 10-year-old today absorbs as background the idea that there are rules in war. Her grandparents' generation absorbed that idea as a novelty. Her great-great-grandparents' generation had no such framework at all. The moral architecture of ordinary people is built partly out of sediment left by codification.

This is the slow ratchet. It is how the humane becomes default, by becoming law first.

IHL is under more direct pressure today than at any point since 1949. Several reasons.

Non-state actors. ISIS, Boko Haram, Al-Shabaab, various ethnic militias. These groups often explicitly reject IHL. They are hard to deter through a framework designed for state actors.

Asymmetric warfare. Drones, remote operations, cyber. The traditional categories of combatant/non-combatant, battlefield/civilian space, strain under new technologies.

Great-power defiance. Russia's invasion of Ukraine has involved mass violations — targeted attacks on civilians, deportation of children, execution of POWs. The war is documented in real time. Accountability mechanisms (ICC warrants, the planned Special Tribunal for the Crime of Aggression) are running in parallel.

Democratic backsliding. Domestic commitments to international legal bodies have weakened in several major democracies. Threatening sanctions on the ICC, for example, has become a more common political move.

Information warfare. Campaigns to portray violations as justified, or to flood the information space with false equivalences, complicate the accountability story. "Both sides" framings obscure asymmetric guilt.

Against these strains, the system still functions — more NGOs monitor more conflicts more systematically than ever before, forensic science on mass graves is more precise than ever, universal jurisdiction prosecutions are increasing. The question is whether the ratchet can keep moving despite the counterforces.

The protection gap. For any given war, ask: who is the law supposed to protect, and who is actually being harmed? The gap between those two sets is the protection gap. The gap tells you where the law is failing — not where the law is absent, but where it exists and doesn't reach.

The before/after test. When a new treaty is ratified, compare the 20 years before to the 20 years after, in the kinds of violations the treaty targets. This is the test the Mine Ban Convention, for example, can credibly pass — landmine use and casualties declined significantly after 1997, though the decline plateaued in recent years.

The namability test. Has the treaty put a name on a category of harm that did not previously have one? "Apartheid" as a crime against humanity. "Ecocide" as a proposed new category. "Enforced disappearance." "Genocide" itself — a word coined by Raphael Lemkin in 1944. Naming is the first act of containing.

The reciprocity question. IHL traditionally relies on reciprocity — both sides follow the rules because breaking them invites breaking in return. Asymmetric conflict weakens reciprocity. When one side has no intention of following the rules, the mutual-deterrence logic collapses. What replaces it? This is the open question of contemporary IHL.

- Dunant, Henri (1862). Un Souvenir de Solferino. - Geneva Conventions I–IV (1949) and Additional Protocols I and II (1977). - Rome Statute of the International Criminal Court (1998). - ICRC Customary IHL Database — the authoritative compilation of customary rules. - Best, Geoffrey (1994). War and Law Since 1945. Oxford University Press. - Neff, Stephen C. (2005). War and the Law of Nations: A General History. Cambridge University Press. - Sassòli, Marco (2019). International Humanitarian Law: Rules, Controversies, and Solutions to Problems Arising in Warfare. - Moyn, Samuel (2021). Humane: How the United States Abandoned Peace and Reinvented War. A critical take. - Sands, Philippe (2016). East West Street. On the Nuremberg origins of "genocide" and "crimes against humanity." - Power, Samantha (2002). A Problem from Hell: America and the Age of Genocide. - Bass, Gary (2000). Stay the Hand of Vengeance: The Politics of War Crimes Tribunals. - Schabas, William (2020). The International Criminal Court: A Commentary on the Rome Statute.

1. The name check. Pick a conflict currently in the news. For each major event reported, identify what category under IHL it falls into (if any) — attack on civilians, attack on medical facilities, use of prohibited weapons, treatment of POWs. What is the gap between what is happening and what the law says? How would you close it?

2. The personal rule book. Write your own short list of things you believe cannot be done to a human being, ever. Compare it to the IHL list. Where do you go further? Where does the law go further than you? Where are the gaps? Does writing them down change how you hold them?

3. The accountability thought experiment. Imagine you are designing a new international criminal court from scratch in 2026, learning from the ICC's first 25 years. What would you do differently? Who would have jurisdiction over whom? What would trigger investigations? How would you handle great-power defiance?

4. The ratchet trace. Pick one behavior that used to be acceptable and is now broadly considered unthinkable — public executions, slavery, child labor, torture. Trace the timeline of how that move happened. What role did law play? What role did storytelling? What role did economics? What does this tell you about how to move the next ratchet?

5. The Dunant question. Henri Dunant went to Solferino for a business meeting and ended up building the Red Cross. He was not a doctor, not a lawyer, not a diplomat. He had seen something and could not un-see it. What have you seen that you cannot un-see? What would you build?

Law 1 — "we are human" — is slow. IHL is Law 1 given legal form, slowly, over 160 years, forcing the argument to happen not in someone's conscience but in a treaty room with representatives of 196 states.

The claim of shared human value does not need war to mean something. But in war it means the most, because war is the setting most hostile to it. The fact that IHL exists at all — that in the middle of armies killing each other, there is a body of law that says do not kill hospital staff, do not torture prisoners, do not starve civilians — is the hardest-won and in some ways most surprising artifact of human civilization.

The law does not stop the worst. It narrows the field of the acceptable. It builds record. It enables, over time, a kind of accountability that was not available to previous generations. The slow ratchet of shared humanity, written in legal prose, carried forward by a million small decisions to prosecute, document, testify.

Every person said yes once, on a summer evening in Castiglione, for three days and nights of bandaging strangers. Tutti fratelli. The rest is infrastructure.