New York, 1863: The Lieber Code: Humanity in Warfare

At Columbia College, the legal scholar Francis Lieber (1798–1872) prepared a code afterwards named after him which helped to govern the conduct of Unionist soldiers during the U.S. Civil War. The Lieber Code is widely regarded as the founding document of the laws of war in the way we know them today. The text, promulgated as General Orders No. 100 by President Lincoln, 24 April 1863, under the title ‘Instructions for the Government of Armies of the United States in the Field’ was drafted amidst the bloody war between the Union and its rebellious Confederate enemy. The salient points of the Code are as follows: it helped to clarify the status and treatment of prisoners of war, irregulars, and that of ‘black prisoners’, it embraced a very distinct notion of military necessity and humane suffering, and it represented the first major comprehensive body of rules for modern warfare in the United States – and far beyond.

In 1827, Lieber had come to the United States as a political refugee. After working amongst others as an editor of the Encyclopaedia Americana’, he started in 1835 teaching law and history at different academic institutions, including Columbia College, where he finally wrote the famous Code. Having grown up in Prussia, fought in the tumultuous years of the Napoleonic Wars, and lost one of his sons during the US Civil War, Lieber was a true product of conflict and who had suffered tremendously during it. These lifetime experiences, as well as his prodigious study of the nature of warfare, deeply informed his work. Indeed, Lieber was among those who helped to create a lasting schism within the laws of war – today better known as international humanitarian law (IHL) – between two clashing, though occasionally overlapping notions of suffering in wartime: one arguing fiercely against making soldiers suffer unnecessarily, the other instrumentalizing suffering even of non-combatants so as to end wars and prolonged suffering quickly.

Franz Lieber (between 1855 and 1865, Library of Congress Prints and Photographs Division. Brady-Handy Photograph Collection). By Mathew Brady [Public domain], via Wikimedia Commons.

Unlike his contemporary Henri Dunant, the founder of the international Red Cross movement, Lieber was a student of the practice of war. He was deeply influenced by the theoretical abstractions of two Prussian thinkers: one was the philosopher Immanuel Kant, the other Carl von Clausewitz, the influential military strategist. Also Lieber was – again unlike Dunant – a veteran of war. As a soldier of the Prussian armies, he had fought against Napoleon’s invading forces, during which he was seriously wounded in 1815; later in 1822 he briefly joined the forces battling for Greek independence. These experiences, stimulated by his own romanticist conception of them, brought Lieber to a very different notion about suffering in wartime than Dunant, whose views on humanity in warfare he had generally few respect for.

Whereas the Swiss humanitarian thought that suffering should be mitigated at all times, Lieber felt the opposite: he claimed that it could be morally good, even necessary, from a military-strategist point of view. Suffering, he wrote, only had to be channeled, along Clausewitzian lines, to inflict maximum pain on the enemy’s forces, thereby shortening the brutality of war. This, he said, symbolized a more humane act than Dunant’s attempt to ban suffering altogether: “The more vigorously wars are pursued,” he wrote, “the better it is for humanity. Sharp wars are brief.” For Lieber, it was all about balancing the demands of humanity with those of military necessity – this perhaps was his most fundamental and foundational contribution to the history of thinking about humanity in warfare.

It led him to accept, amongst other things, the principle that, in case of a siege, the commander could potentially use starvation as a weapon against his enemy. In Article 17, for instance, Lieber noted that it was ‘lawful to starve the hostile belligerent (...) so that it leads to the speedier subjection of the enemy.’ In the next article, he stated that it was ‘lawful, though an extreme measure, to drive [non-combatants] back, so as to hasten on the surrender.’ This view of military necessity, by allowing commanders to turn fleeing civilians back to their besieged city, was later also confirmed by the Nuremberg Military Tribunals. Although controversial, considering the 1977 Additional Protocol I and its banning of starvation of civilians in besieged urban areas, it is in fact a legal principle still regarded by many, though definitely not all, international jurists, like the eminent Israeli lawyer Yoram Dinstein, as a lawful one.

Lieber’s instrumentalist view on humanity in warfare – permitting forms of inhumanity so as to end wars and their horrors quickly – also formed the basis of the Code he produced during the US Civil War. At the time, the war absorbed three of Lieber’s own sons, who were fighting on opposite sides – one for the Confederacy, the others for the Union. The problem of irregulars was a major concern leading up to the drafting of the General Order 100. In 1862, Lieber had been asked by the General-in-Chief Henry Halleck of the Union forces his opinion on how to regulate forms of irregular warfare and he authored a brochure entitled: Guerrilla Parties. Shortly afterwards, President Abraham Lincoln asked him to draft a set of rules to serve as a guideline for the Unionist forces fighting the rebellious Confederacy. It covered a wide range of topics, including the destruction of property, poisoning, spies, the protection of POWs, as well as the problem of slavery.

Lincoln’s 1863 Emancipation Proclamation calling for freeing Southern slaves, and its implications for Lieber’s notions of irregular warfare, resulted in a major legal challenge: by law, slaves were considered property, not lawful combatants. When forces captured armed black men, they were to be treated as criminals liable to re-enslavement or the death penalty. Under customary law, liberating them would be considered a criminal act by destroying enemy property without any reason of military necessity. Lincoln sought to challenge these established legal notions and instructed Lieber to sanction the practice of arming black men. Consequently, Lieber’s code included a ban on slavery, and that every captured person, regardless of color, was entitled to freedom and remained ‘under the shield of the law of nations’ (Article 43).

When Southerners heard about Lieber’s propositions, they furiously demanded their annulment. Lincoln responded, in turn, by directly halting the exchange of prisoners of war. This decision to put pressure on the South’s slave regime, brought serious misery to the Confederate POW-camps, where imprisoned Unionist soldiers lived under dire circumstances due to a lack of food, medical care, and so on. Lincoln ignored requests, however, from their families to re-start the policy of prisoner exchange, as he knew that the Southern army – unlike his own – was in desperate need of manpower. Moreover, he thought that his decision to temporarily stop those exchanges served, in the end, the right cause – i.e., the abolition of slavery. This despite the fact that his policy, partly inspired by Lieber’s dictum of ‘sharp wars are brief’, caused what legal historian John Fabian Witt (whose own book is named after the Code’s initiator) has called ‘a humanitarian nightmare’: the death of tens of thousands of POWs.

The Lieber Code had thus both humanitarian and non-humanitarian impulses and consequences. Since its 1863 inception, it has further gained widespread support and has been translated by eminent jurists like Johann Kaspar Bluntschli, an influential Swiss legal scholar who corresponded with Lieber, into various languages. Its principles have also been included in numerous European and non-European field manuals and declarations, first during the Austro-Prussian War of 1866 and then the Franco-Prussian War (1870–1871) by the Prussian army. They were, in conjunction with Dunant’s endeavor to protect certain categories of victims of war, particularly sick and wounded soldiers, widely discussed as part of the first international conferences on the laws of land warfare in Brussels (1874) and The Hague (1899 and 1907).

The Lieber Code strongly influenced certain jurists and statesmen attending that conference in the metropolitan Belgian capital, where they established the first comprehensive set of rules for the ‘civilized’ conduct of European warfare. One of these participants was the young Russian (and German-speaking) jurist Fyodor Martens, who had studied the Lieber Code extensively and explicitly praised it as a ‘blueprint for his own draft,’ according to historian Peter Holquist. Following the outrage about the Franco-Prussian War, with its summary executions of numerous so-called francs-tireurs, Martens himself had called for an international conference on the laws of land warfare; in fact, he had helped to design its first drafts, which set out the future drafting process and, ultimately, in tandem with the Lieber Code, formed the basis upon which the founding articles of the Hague and Geneva Conventions were established. For some historians and jurists – though not everyone – the Code itself is understood to have had ramifications for the Geneva Conventions of 1949, the most important rules for the conduct of today’s armed conflicts, as they accepted, for example, some of its notions on how to conduct siege or irregular warfare.

Further Reading

This body of references includes both historical and legal canons of cutting-edge academic scholarship, in particular two important contributions made by John Fabian Witt, a chronicler of the laws of war in the nineteenth century of U.S. history and Lieber’s best biographer. Other further readings include references on the contributions made by fellow contemporaries of Lieber (e.g. Fyodor Martens), the rise of new rules throughout the nineteenth century for the treatment of prisoners of war and irregulars, the law’s most important documents, and an anthology of its long-term historical developments.

Short Biographical Note on Contributor

Boyd van Dijk is a History PhD student at the European University Institute (EUI) in Florence, where he works on the international history of the laws of war. He received degrees in political science and history from the University of Amsterdam and Columbia University. In 2013, he published a Dutch monograph on the history of KL Herzogenbusch and its neighbours. He was a participant of the Global Humanitarianism Research Academy (GHRA) 2015.