Boer War

...Thus the Boers struck first in self-defense in October 1899, besieging British garrisons in towns named Mafeking, Ladysmith, and Kimberley, and defeating British relief columns in battles at places named Spion Kop, Vaal Kranz, Magersfontein, Stormberg, and the Tugela River: 20% of Sir William Gatacre’s 3,000 troops captured at Stormberg as British troops fled after being sent up a near-cliff against entrenched Boers with rifles; 10% of Lord Methuen's 14,000 killed or wounded at Magersfontein as they assaulted the Boer trench line; and Buller's 21,000 suffering 1200 killed and wounded to the Boers’ 50 in a failed attempt to cross the Tugela River. Any cost-benefit analysis done at this point would have led to an obvious conclusion: back down. Protest that the war was a mistake, and have some chair-polishing leading to British promises to respect the independence and autonomy of the Boer Republics and Boer promises to respect the rights and liberties of British-flag immigrants.

That is not what happened.

The Boer Afrikaans-speaking population of the Transvaal and the Orange Free State was 200,000.

The British sent 500,000 soldiers to South Africa starting in February 1900—the same proportional manpower commitment as four million would be for the U.S today. The British sent a competent general—Field Marshal Lord Roberts. They outnumbered even the total mobilization of Boer military manpower by fifteen to one. The Orange Free State capital Bloemfontein fell on March 13, Johannesburg on May 31, and Transvaal capital Pretoria on June 5.

The reaction at home in Britain to victories was as if the country had won the World Cup in soccer: half a million British soldiers could defeat armies one-fifteenth their size!

...Nearly 100,000 people died in the Boer War: in addition to the 30,000 Boer civilians, perhaps 8,000 British battle deaths, 14,000 British soldiers dead of disease, 10,000 Boer soldiers, and perhaps 30,000 Africans—nobody counted them. Britain mobilized 2.5% of its adult male population for the war. One in ten of those died.

-Brad Delong, Slouching Towards Utopia