The Lincoln Laws
Should we thank the Great Emancipator for codifying the law of war—or curse him?
Photo courtesy the National Archives and Records Administration.
In 1861, the Southern states seceded from the Union. Lincoln and other Northern leaders saw secession as treason and the South’s leaders and soldiers as criminals who should be caught, tried, and hanged. At the same time, to prevent Britain and other foreign countries from trading with the South, Lincoln declared a blockade, which, under the law of war, entitled the U.S. Navy to seize foreign vessels that tried to trade with the South. However, the law of war presumes a conflict between two states. If the law of war applied to the conflict, then Southerners could not be criminals; they were enemy soldiers of a foreign state and thus could be detained for the duration of hostilities but not tried or executed.
Thus, for one purpose, the Confederacy was a criminal organization; for another purpose, it was an enemy nation. Lincoln later decided to grant prisoner of war protections to captured enemy soldiers, but only because the South made clear that it would retaliate against captured Union soldiers if the North prosecuted Southerners. Later, after Lincoln’s death, the government again decided to prosecute the leaders of the Confederacy as criminals, but eventually abandoned the effort in response to various political and legal difficulties.
Foreign diplomats enjoyed the sight of our moralistic young nation undergoing linguistic gymnastics in order to claim that right always supported its national interest. But larger issues were at stake, and they are the subject of a new book, John Witt’s Lincoln’s Code. It’s worth revisiting these legal conundrums not only because they’re interesting, but also because they take us back to the origins of a codified law of war, and raise still-pertinent questions about the usefulness of having such laws. The law of war has played a central role in debates about American policies toward al-Qaida under Presidents Bush and Obama, with critics frequently arguing that the U.S. government has violated the law of war or improperly cited it as support for its policies. Witt’s historical account helps explain why both administrations felt it necessary to deviate from a strict interpretation of international law.
The blockade was hardly the only issue where the Lincoln administration found itself in an awkward position with respect to the law of war. The law of war posed problems when it came to emancipation as well. As Lincoln initially acknowledged, freeing the slaves was probably a violation of the law of war. Slaves were property, and while the law of war permitted armies to seize or destroy enemy property for military objectives, emancipation was different because the property it destroyed was not required for the Union war effort. As Lincoln put it 1861, “If the General needs them [slaves], he can seize them, and use them; but when the need is past, it is not for him to fix their permanent future condition.” Lincoln later shook off these scruples, emancipating the slaves in the Confederacy in 1863.
The other great example of law-of-war violations in the Civil War is Sherman’s march through Georgia. Sherman, with Lincoln’s blessing, ordered his troops to live off the land and destroy everything in their path. The general is often credited with (or blamed for) anticipating the “total war” of the 20th century, where the goal was not so much to destroy enemy armies as to undermine public morale and hence political support for the war effort by inflicting misery on innocent civilians. The law of war at the time of the Civil War did not embrace this newfangled form of warfare, and it prohibited the targeting of civilians. But Sherman disregarded the law for the sake of winning the conflict.
For many observers, these examples admit of only one conclusion: that Lincoln chose to violate the laws of war when they stood in his way. He did not violate all the rules, but if one gets to pick and choose which rules to obey and which to violate, then the law lacks binding force. The law of war, which at the time was customary rather than embodied in treaties, was not worth the paper it wasn’t written on. Enthusiasts for the way that the Bush administration disregarded or rewrote the law of war to address the threat from Al Qaeda and the Taliban could cite none other than the sainted Lincoln as precedent.
Witt believes that this view is too simple. He agrees that Lincoln did not always follow the rules, yet he regards Lincoln as a pragmatist rather than as a criminal. What’s the difference? Witt points out that Lincoln did much to advance the law of war. In 1863, under Lincoln’s authority, a military theorist named Francis Lieber drafted a code of military conduct that became known among international lawyers as the Lieber Code, though Witt prefers to call it Lincoln’s Code, the title of his book. The Lieber Code codified large swaths of the unwritten customary laws of war and modified them where necessary to serve the Union’s immediate war aims—most notably in provisions that authorized belligerents to emancipate slaves owned by persons in enemy countries and that banned discrimination against soldiers on the basis of race. The code was also notable in its insistence that “military necessity” trumped (nearly) all of the substantive rules it contained. So although the Code humanely prohibited belligerents from executing POWs, it also grimly permitted them to do so in the service of “military necessity.” All that was ruled out was private violence or sadistic cruelty.
It is a striking fact that Lincoln promulgated the Lieber Code not just as a purely internal set of rules to maintain discipline within the Union Army, but also asserted that it reflected international law and demanded that Confederate armies comply with it as well. The South naturally cried foul, arguing that the slave emancipation provision had no roots in the traditional law of war and merely served the Union’s military interests. Nonetheless, the code provided a basis for partial cooperation between the North and South. The South rejected some provisions, but where the belligerents agreed—for example, as to provisions relating to the treatment, parole, and exchange of POWs—they cooperated.
The Lieber Code also contributed to the development of the international law of war. Before Lieber, belligerents frequently disagreed over the law of war because no authoritative document embodied it. Scholars sought to codify the law of war in treatises, but they disagreed with each other and the treatises exerted little authority. Lieber, by contrast, presented the traditional law of war—with his own modifications—in a way that gained not only the approval of the United States government, but also the favor of foreign governments, which soon created their own versions of it. Lieber’s Code and its successors influenced the negotiations that produced formal law-of-war treaties at the Hague and Geneva at the end of the 19th century and in the 20th.
Still, how do we reconcile these developments with Lincoln’s picking and choosing among the laws? After all, if Lincoln could choose which laws to obey, why couldn’t future leaders, in the United States and other countries, do the same? The law of war would be an a la carte menu rather than anything like what we mean by “law.”
Eric Posner, a professor at the University of Chicago Law School, is a co-author of The Executive Unbound: After the Madisonian Republic and Climate Change Justice.