The cost of jumping in was appalling. Just over 700,000 British soldiers were killed. The numbers are so staggering that it can be hard to contemplate, and one really needs to imagine oneself in the middle of the mud and smoke to grasp what this horror was like, how poorly it was managed, and the horrendous betrayal of the fighting man’s idealism. 

Rudyard Kipling’s son, John, was so desperate to serve despite his poor eyesight that his father pulled strings to get him into the Irish Guards. He was killed at the Battle of Loos in 1915. If you visit the Kipling residence at Bateman’s, East Sussex, John’s room is left as it was when he was a boy - his school uniform hanging up in the cupboard.

Treasure was lost as well as blood. By the war’s end, Britain was saddled with massive debts and world economic power shifted from Europe to America - a nation that wasn’t yet ready for its new role and quickly retreated into isolationism and tariffs (which would have devastating consequences after the 1929 Wall Street Crash). Our global position was permanently undermined; British society was radicalised. 

It’s particularly odd that conservatives so often favour war: its effect is always to expand the state and hasten social transformation. Before the war, ours was a deeply uneven, often unfair society (riven by class conflict), but we had accepted the moral challenge of poverty and attempted piecemeal change. The War accelerated the rebalancing Britain away from the laissez-faire model and decisively towards the welfare/warfare state.

Overseas, the conflict put the Bolsheviks in power because they recognised the need to end the war as quickly as possible on any terms. Great empires were destroyed; nationalism unleashed. Hitler and Mussolini were direct products of the conflict, of that futurist, Darwinist image of man as part of a merciless machine.