At the beginning of World War I, like many other writers, Kipling wrote pamphlets and poems which enthusiastically supported the UK's war aims of restoring Belgium after that kingdom had been occupied by Germany together with more generalised statements that Britain was standing up for the cause of good. In September 1914, Kipling was asked by the British government to write propaganda, an offer that he immediately accepted. Kipling's pamphlets and stories were very popular with the British people during the war with his major themes being glorifying the British military as the place for heroic men to be, German atrocities against Belgian civilians and the stories of women being brutalized by a horrific war unleashed by Germany, yet surviving and triumphing in spite of their suffering.
Kipling was enraged by reports of the Rape of Belgium together with the sinking of the RMS Lusitania in 1915, which he saw as a deeply inhumane act, which led him to see the war as a crusade for civilization against barbarism. In a 1915 speech Kipling declared that "There was no crime, no cruelty, no abomination that the mind of men can conceive of which the German has not perpetrated, is not perpetrating, and will not perpetrate if he is allowed to go on...Today, there are only two divisions in the world...human beings and Germans."
Alongside his passionate antipathy towards Germany, Kipling was privately deeply critical of how the war was fought by the British Army as opposed to the war itself, which he ardently supported, complaining as early as October 1914 that Germany should have been defeated by now, and something must be wrong with the British Army. Kipling, who was shocked by the heavy losses that the BEF had taken by the autumn of 1914 blamed the entire pre-war generation of British politicians, who he argued had failed to learn the lessons of the Boer War and as a result, thousands of British soldiers were now paying with their lives for their failure in the fields of France and Belgium.
Kipling had scorn for those men who shirked duty in the First World War. In "The New Army in Training" (1915), Kipling concluded the piece by saying:
This much we can realise, even though we are so close to it, the old safe instinct saves us from triumph and exultation. But what will be the position in years to come of the young man who has deliberately elected to outcaste himself from this all-embracing brotherhood? What of his family, and, above all, what of his descendants, when the books have been closed and the last balance struck of sacrifice and sorrow in every hamlet, village, parish, suburb, city, shire, district, province, and Dominion throughout the Empire?
Death of son
Kipling actively encouraged his young son to go to war. Kipling's son John died in the First World War, at the Battle of Loos in September 1915, at age 18. John had initially wanted to join the Royal Navy, but having had his application turned down after a failed medical examination due to poor eyesight, he opted to apply for military service as an Army officer. But again, his eyesight was an issue during the medical examination. In fact, he tried twice to enlist, but was rejected. His father had been lifelong friends with Lord Roberts, commander-in-chief of the British Army, and colonel of the Irish Guards, and at Rudyard's request, John was accepted into the Irish Guards.
He was sent to Loos two days into the battle in a reinforcement contingent. He was last seen stumbling through the mud blindly, screaming in agony after an exploding shell had ripped his face apart. A body identified as his was not found until 1992, although that identification has been challenged.
After his son's death, Kipling wrote, "If any question why we died/ Tell them, because our fathers lied." It is speculated that these words may reveal his feelings of guilt at his role in getting John a commission in the Irish Guards. Others such as English professor Tracy Bilsing contend that the line is referring to Kipling's disgust that British leaders failed to learn the lessons of the Boer War, and were not prepared for the struggle with Germany in 1914 with the "lie" of the "fathers" being that the British Army was prepared for any war before 1914 when it was not.
John's death has been linked to Kipling's 1916 poem "My Boy Jack", notably in the play My Boy Jack and its subsequent television adaptation, along with the documentary Rudyard Kipling: A Remembrance Tale. However, the poem was originally published at the head of a story about the Battle of Jutland and appears to refer to a death at sea; the 'Jack' referred to is probably a generic 'Jack Tar'. Kipling was said to help assuage his grief over the death of his son through reading the novels of Jane Austen aloud to his wife and daughter.
During the war, he wrote a booklet The Fringes of the Fleet containing essays and poems on various nautical subjects of the war. Some of the poems were set to music by English composer Edward Elgar.
Kipling became friends with a French soldier whose life had been saved in the First World War when his copy of Kim, which he had in his left breast pocket, stopped a bullet. The soldier presented Kipling with the book (with bullet still embedded) and his Croix de Guerre as a token of gratitude. They continued to correspond, and when the soldier, Maurice Hammoneau, had a son, Kipling insisted on returning the book and medal.
On 1 August 1918, a poem—"The Old Volunteer"—appeared under his name in The Times. The next day he wrote to the newspaper to disclaim authorship, and a correction appeared. Although The Times employed a private detective to investigate (and the detective appears to have suspected Kipling himself of being the author), the identity of the hoaxer was never established.