Why were soldiers killed for cowardice in World War 1?

Answer 1

So people don't desert. Would you rather be shot by someone else and die honorably for your country or would you rather be shot by your own guy and die in shame? This was kind of the mentality that the old Generals whose lives are too "important" to risk tried to instill into their troops. Deserters mean more deserters, and eventually you've got an army of nothing. Therefore, you try to stop desertion at its roots. If one guy stands up to a tyrant, and another guy stands up, and then and third, and eventually a lot of guys stand up, you will probably too. Then eventually everyone (or damn close to everyone), the tyrant can do nothing, because if he puts them all to death, he is no longer the ruler of anything.

"To encourage the others", as Voltaire said of the 18th-century British execution of Admiral Byng for failing to "do his utmost" in a botched action. Combat fatigue and shell-shock - forerunners of today's PTSD - were little acknowledged until late in the war. Fear of political subversion sustained a hard line as Russia's revolution and withdrawal from the war threatened to produce echoes in the west: French and Italian troops did indeed refuse to fight in 1917 and British soldiers briefly mutinied at Étaples. During the war the British executed 306, against 80,000 treated for war-related stress: all received a posthumous pardon in 2006, though their sentences were allowed to stand.

Answer 2

306 British and Commonwealth soldiers were executed in WW1 for cowardice.