Absolute obedience has always been regarded as the foundation of military discipline, and disregard of orders or of duty by soldiers has incurred the severest penalties. The execution of Adm Byng in 1757 for ‘failing to do his utmost’ inspired Voltaire to coin the phrase pour encourager les autres, which neatly summarizes the ultimate reason for the practice. From the earliest times, cowardice, desertion, and mutiny were considered to be the most serious military crimes and were punished with death in most armies. When large numbers were involved, the original meaning of ‘decimation’ refers to the custom of drawing lots and executing only one in ten, to preserve numerical strength. No army was ever more given to immediate execution for even trivial offences than the Zulu, and their discipline was legendary.
In Britain in the Middle Ages certain military offences were punished with instant execution. An ordinance issued by Edward I to his army decreed that any man who, through cowardice, abandoned his Lord or his companions should be put to death, and an ordinance of Richard II during the Hundred Years War imposed the death penalty on a soldier who disobeyed orders, left his watch without permission, or ‘spread despondency in the ranks’. During the 17th century flogging was adopted as the principal form of military punishment by the majority of European armies, and in consequence fewer death sentences were passed by their military courts. But when flogging was abolished in the French army during the Napoleonic wars, no fewer than 45 offences again became punishable with execution.
No death sentences were imposed by British courts martial during the Crimean war, and despite the fact that flogging was belatedly abolished in 1881, only one soldier in the British army was executed for desertion during the Second Boer War. But during WW I, 3, 082 officers and men were condemned to death, although the majority of these sentences were commuted to terms of imprisonment. Of the 346 executions actually carried out, 309 were for military offences, mostly desertion and cowardice. This may have been the largest number of executions carried out by any of the European armies, though records are incomplete. Despite the massive mutiny of 1917, only 133 French soldiers were shot up to the end of January 1918 partly thanks to a revival of execution by lot among those condemned. Records of executions in the German army were destroyed, but there may have been some 150 death sentences passed by courts martial and around 48 carried out. Although under US military law, almost unchanged since the American civil war when hundreds were shot, a sentence of death could be passed on any man convicted of desertion, disobedience, sleeping on post, or ‘misbehaviour in the face of the enemy’, no US soldier was executed for a military offence.
Between the world wars many of the major powers reduced the number of capital offences under their military law and executions were rare in the armies of the western Allies during WW II. There were four executions in the British army and only one American soldier was shot, for repeated desertion. The Soviets executed soldiers on an infinitely greater scale, either after due process or as summary military punishment. The Germans, too, imposed the death penalty with increasing frequency, with flying courts martial imposing summary (and often totally unjustified) death penalties in the last weeks of the war. There were probably not less than 15, 000 of such executions. France and Germany have now abolished capital punishment for military offences, but in the British and US armies a death sentence may still be imposed, but only for very few offences of a military character.
— Anthony Babington