IN THE ABSENCE OF PEACE | The Evolution of the Laws of War
For nearly 4,000 years, humanity has tried — and failed — to achieve lasting peace. Yet again and again, the evolution of the laws of war has reflected our attempts to limit the horrors of conflict through agreements and treaties.
Each milestone on this timeline is tied to world events, new technologies, and personal experiences of war. Sometimes those experiences inspire action: never again. Here, we also highlight some of the individuals who devoted their minds, hearts, and hands to justice and peace.
Legend:
- Treaty: a legally binding agreement between states
- Convention: a treaty, often on human rights or the laws of war
- Protocol: an addition or amendment to a treaty
- Resolution: a position or appeal by an international body, usually not legally binding
- Political declaration: a statement of intent by states, without legal obligations
TIMELINE
18th century BCE — Babylon & Mesopotamia
Hammurabi
Hammurabi is the sixth king of Babylon and founder of the Old Babylonian Empire. Between 1792 and 1750 BCE he conquers all of Mesopotamia.
Code of Hammurabi
Known as the oldest collection of laws. The war section obliges soldiers to fight on the king’s command; prisoners of war can ransom themselves.
500 BCE – 200 CE — The Hindu Antiquity
A growing need for order
From 1500 BCE, a complex society emerges in North India. As power and conflict grow, so does the need for order, justice, and rules.
Manu Smriti
A collection of Hindu laws with rules on conduct, justice, and war. Violence must be justified, with respect for prisoners and civilians.
Early 7th century — Early Islam
Abu Bakr
Friend, ally and father-in-law of the Prophet Muhammad; after the Prophet’s death (632) he becomes the first Sunni caliph.
Islamic law per Abu Bakr
Abu Bakr sets clear rules to protect civilians in armed conflict: “Do not let the blood of women, children and the elderly stain your victory.” And: “Do not destroy palm trees, burn no houses or fields, and do not cut fruitful trees.”
697 CE — The Dream of Saint Adomnán
Adomnán and the Synod of Birr
Moved by a dream from his mother, the Irish abbot Adomnán seeks better protection for innocents in war and convenes the Synod of Birr.
Cáin Adomnáin (Law of the Innocents)
Ninety-one kings from Ireland and Great Britain sign what is seen as Europe’s first international treaty. It protects women, children, clergy and the unarmed during war.
1625 — Turmoil in the Dutch Republic
Order and justice
In a time of political chaos, Hugo Grotius argues that war must never be about power alone; it must follow rules, with self-defence and restoring peace as the goal.
On the Law of War and Peace
Before this book, war and law were mainly a theologians’ field. Grotius is the first jurist to reason from universal, rational principles, independent of faith or political power—laying the groundwork for modern international humanitarian law.
ADVOCATE FOR PEACE — Hugo Grotius (1583–1645)
Grotius lives through many conflicts. Even during his imprisonment at Loevestein he works on international law. After his escape he is never allowed to return to the Netherlands. In exile he continues his work on the laws of war. He dies in 1645 in Rostock, Germany, and is buried in the Nieuwe Kerk in Delft.
“One must, as far as possible, prevent the death of innocent civilians, even by accident.”- Hugo Grotius
Image: Le Droit de la Guerre et de la Paix (1724), the French translation of Hugo Grotius’s On the Law of War and Peace.
1863 — The American Civil War
Context
In 1861 war breaks out between the Northern and Southern states. Existing rules from 1806 say nothing about armed civilians or how to distinguish civilians from soldiers.
The Lieber Code
In 1863, Francis (Franz) Lieber writes a code of conduct for the Union army. It bans looting, injuring, raping or killing the population of an occupied area.
ADVOCATE FOR PEACE — Francis (Franz) Lieber (1798–1872)
Born in Berlin, Lieber fights as a young man against Napoleon and in the Greek War of Independence, witnessing war’s effects first-hand. At 29 he emigrates to the U.S., and from 1860 teaches political science at Columbia University. Beyond the Lieber Code he writes on equal rights and abolishing slavery.
“Unnecessary killing, or killing for revenge, is forbidden.” -Francis Lieber
Image: Professor Francis Lieber, c. 1860.
1864 — The Battle of Solferino
Witness to horror
Seeing the carnage at Solferino, Henry Dunant calls for international rules and neutral, trained volunteers to aid the wounded. This leads to the first Geneva Convention and the founding of the Red Cross.
Geneva Convention
Signed by all states worldwide. It obliges parties to care for the wounded on the battlefield—regardless of nationality—and protects medical workers and the Red Cross emblem.
ADVOCATE FOR PEACE — Henry Dunant (1828–1910)
Henry Dunant, a Swiss banker, witnesses the aftermath of Solferino in 1859. Thousands lie without help. Deeply moved, he writes A Memory of Solferino, urging clear state agreements and a permanent volunteer corps. His core principle: neutrality—help for friend and foe alike. In 1901 he receives the first Nobel Peace Prize.
“Tutti fratelli — we are all brothers.” – Henry Dunant
Image: Henry Dunant, photographer unknown, taken c. 1850–1860.
1899 & 1907 — Arms Race & The Hague Peace Conferences
Rising tension
France and Russia conclude a secret defence pact; Germany withdraws from agreements with Russia. New technology fuels an arms race.
The Hague Peace Conferences
Two conferences adopt 20 treaties, including rules on new technologies (e.g., balloons, exploding bullets) and new protections for prisoners of war, civilians and cultural property.
ADVOCATE FOR PEACE — Bertha von Suttner (1843–1914)
The Austrian pacifist experiences the Russo-Turkish War and responds with the novel Lay Down Your Arms!. She lectures, organizes congresses and builds peace movements, helping pave the way for The Hague conferences and the Peace Palace (with Andrew Carnegie). In 1905 she becomes the first female Nobel Peace laureate.
“A vital part of our strength seems lost to oblivion.” – Bertha von Suttner
Image: Bertha von Suttner, 1906.
26 June 1945 — World War II & The UN Charter
Never again
The deadliest war ends with the first atomic bomb. Some 25 million civilian deaths include the systematic persecution and murder of about six million Jews, and of Roma and Sinti. The world agrees: never again.
United Nations Charter
Allied nations meet in San Francisco to build a world without war and poverty. The Charter sets duties for peace and security and clarifies when war may be justified—echoing Books I–II of Grotius’ De iure belli ac pacis (jus ad bellum). Signed by 51 states then; today, 193.
1949
New agreements after the Second World War
In response to the immense suffering of war, states come together to set rules to prevent unnecessary harm during armed conflicts. The International Committee of the Red Cross is the main organizer of this conference and plays an active role in the preparation and negotiations.
The Geneva Conventions
The nineteenth-century Geneva agreements continued to evolve, with the most important expansion in 1949. Four conventions are adopted, signed by all countries worldwide. They set out the protection of the wounded on land and at sea, the treatment of prisoners of war, and the protection of civilians in wartime.
1954
Destruction during the Second World War
During the war, countless monuments, museums, archives and religious buildings were deliberately attacked, looted or destroyed. In its aftermath grew the realization that cultural heritage also needs stronger protection.
The Hague Convention for the Protection of Cultural Property
This convention requires states to spare cultural heritage in wartime. Cultural property must not be deliberately targeted. The Blue Shield indicates what must be protected.
1970 — Fear of Nuclear War & The NPT
Non-Proliferation Treaty (NPT)
After Hiroshima and Nagasaki, concern over nuclear weapons grows. The NPT aims to stop their spread: non-nuclear states pledge not to acquire them; nuclear states commit to disarmament talks. Peaceful nuclear energy remains accessible. Nearly all states sign.
ADVOCATES FOR PEACE — “Make love, not war”
As a child, Yoko Ono survives the bombing of Tokyo. In 1969 she and John Lennon stage the famous “Bed-in” as a peaceful protest against the Vietnam War.
“Declare it. Just the same way we declare war. That is how we will have peace… we just need to declare it.”— John Lennon (1940–1980)
Image: Yoko Ono and John Lennon in the Hilton Hotel Amsterdam during their 1969 Bed-In.
ADVOCATES FOR PEACE — Doctors Without Borders (MSF)
During the Biafra War (Nigeria, 1967–1970) famine is widespread and access is blocked. Two French Red Cross doctors see politics hindering aid and in 1971 found Médecins Sans Frontières. MSF delivers independent medical aid—regardless of side—and speaks out publicly about violations of the laws of war, unlike the Red Cross which relies on confidential dialogue to maintain access.
“Where the need is greatest, we are there… we go all-out for our patients.” — MSF mission
Image: Doctors Without Borders (Médecins Sans Frontières).
1972 — The Vietnam War & The Biological Weapons Convention
War on screen
Napalm and Agent Orange cause devastating harm to people and nature; for the first time, mass media bring the war into living rooms.
Biological Weapons Convention
Building on earlier ICRC proposals (1956), states adopt new protocols after Vietnam: rules on chemical, nuclear and biological weapons, including bans on developing, producing and stockpiling bacteriological or toxin weapons.
ADVOCATES FOR PEACE — Global Protests
Dubbed the first “television war”, Vietnam sparks mass protests in the U.S. and Europe, including major demonstrations in the Netherlands.
“If we can change the world, why not from Nijmegen?” — Koos van Zomeren
Image: Demonstration against the war in Vietnam and Cambodia (in Nijmegen), 1975.
1976
Fear of environmental modification
During the Cold War, states experiment with influencing the weather. Fears grow that such methods could be used as weapons.
Environmental Modification (ENMOD) Convention
Bans the use of environmental modification as a means of warfare. States may not manipulate climate, nature or geophysical processes for hostile purposes.
1977
Warfare is changing
After 1945, civil and guerrilla wars increasingly affect civilians; internal conflicts remain weakly regulated.
Additional Protocols to the Geneva Conventions (1977)
Two protocols expand protection for victims—civilians and wounded fighters—in both international and non-international armed conflicts.
1980
Limits on “conventional” weapons
Experience from conflicts like Vietnam shows that some common weapons cause excessive injury or indiscriminate effects.
Convention on Certain Conventional Weapons (CCW)
Bans or restricts weapons such as incendiaries, mines and booby traps.
1987
Toward the end of the Cold War
Nuclear tensions peak in Europe; protests surge. With Gorbachev and Reagan moving closer, disarmament becomes possible.
Intermediate-Range Nuclear Forces (INF) Treaty
Eliminates missiles with ranges of 500–5,500 km and allows on-site inspections—unprecedented at the time.
1993
No more poison gas
Iraq’s use of chemical weapons against Iran and Kurdish civilians shows that gas is no relic of the past.
Chemical Weapons Convention (CWC)
Bans the production, stockpiling and use of chemical weapons and requires destruction of existing stocks; the OPCW verifies compliance.
2000
Child soldiers
Worldwide, children are forced to fight; earlier rules prove insufficient.
Optional Protocol on the involvement of children in armed conflict (2000)
Raises the minimum age for participation in hostilities from 15 to 18, also applies to non-state armed groups.
ADVOCATE FOR PEACE — Malala Yousafzai
The Pakistani activist fights for the right to education. Shot by the Taliban at 14, she continues her work with her foundation. In 2013 she wins KidsRights’ International Children’s Peace Prize.
“If you want to end war, instead of sending guns, send books. Instead of tanks, send pens. Instead of soldier, send teachers.” – Malala Yousafzai
Image: Malala Yousafzai, 2014.
ADVOCATE FOR PEACE — Divina Maloum
From Cameroon, Divina stands up against recruiting child soldiers, exploitation and abuse. With Children for Peace, over 3,000 drawings make children’s experiences visible and empower youth to speak up. In 2019 she wins KidsRights’ International Children’s Peace Prize.
“If you stand up for a cause, be prepared to stand alone like a tree. And if you fall, fall like a seed that grows back to fight again.” – Davina Maloum (2003)
Image: Divina Maloum wearing the Children for Peace T-shirt, 2019.
ADVOCATES FOR PEACE
Sofiia Tereshchenko, Anastasiia Feskova & Anastasiia Demchenko
Nearly 3.5 million children are currently on the move alone. Experiencing war in Ukraine, the three volunteers build an app to help unaccompanied children find food and safe shelter. In 2023 they win KidsRights’ International Children’s Peace Prize.
“At any point in your life, do not give up. There will always be new opportunities that you might have never even dreamed of.” – Sofiia Tereshchenko, 2005
Image: Sofiia Tereshchenko, Anastasiia Feskova & Anastasiia Demchenko
2022
More civilian casualties in cities
Missiles and artillery in urban areas cause rising civilian harm and destroy vital infrastructure; the environment suffers lasting damage.
Political Declaration on Explosive Weapons in Populated Areas (EWIPA)
83 states pledge to limit heavy explosive weapons in populated areas.
ADVOCATES FOR PEACE — The Red Line Demonstration (The Hague, 2025)
On 18 May 2025 over 100,000, and on 15 June 2025 even more than 150,000 people form a “red line” from the Malieveld to the Peace Palace, protesting the cabinet’s stance on Israel. Organized by MSF, Amnesty, Oxfam Novib and others, it is the largest Dutch demonstration in two decades.
“We draw the red line for Gaza!” – protesters
Image: The first Red Line Demonstration in The Hague.
2025 and onwards
Artificial intelligence in weapons
More systems use AI—for example autonomous drones with minimal human control. Even where law lags behind, the Martens Clause affirms protection for civilians and combatants.
EU AI Regulation
In early 2025, the EU adopts rules for the responsible development and use of AI in weapons; there is still no binding global treaty on autonomous weapon systems.
INTERNATIONAL HUMANITARIAN LAW TODAY
After centuries of agreements, IHL remains vital—from Gaza and Ukraine to Sudan, Yemen, Syria, Afghanistan, Myanmar and Congo. Core principles endure: protect people, limit violence, preserve humanity in war. One of the hardest rules is proportionality: civilian harm is not per se illegal, but force must be proportionate to the military goal—drawing that line is difficult.
THE ROLE OF THE RED CROSS AND MSF
The Red Cross is neutral and aids victims worldwide: medical care, registering prisoners of war, protecting hospitals. The Geneva Conventions mandate it as an impartial intermediary between parties. It works through quiet diplomacy rather than public statements.
Doctors Without Borders (MSF) also provides medical aid, independently—and can publicly speak out about abuses.
KEY RULES OF THE LAWS OF WAR
- Who is a lawful target? Civilians must never be targeted deliberately. The same applies to civilian objects (homes, schools, shops).
- What must be protected? Healthcare workers, ambulances and hospitals are not military targets.
- How to treat victims? The wounded must receive care; the dead must be treated with respect. Prisoners must not be ill-treated.