As November 1900 rolled around, Roberts, Salisbury and the rest of the political and military leadership of Great Britain were feeling quite pleased with themselves. While much of the Boer soldiers were still unaccounted for, they had full control of all but the northern part of the Transvaal. It was good enough for the commanding general, and he passed on command to Kitchener to handle the mopping up operations. The equivalent of a Mission Accomplished banner was unfurled, and many of the more professional units were cycled out for local militia and yeoman troops. In London Lord Salisbury got to proclaim the kind of victory every politician wants, and was swept back into office with a strong mandate in the so-called Kakhi Elections. Though many liberals were unsettled by the conquest of the Boers, it was quite challenging for them to speak out against a successful war.
Then in December the Boer forces kicked their antics into high gear. De Wet and the other Boer leaders had never really stopped fighting. As far back as May 1900 he had switched to guerilla tactics, ambushing a column of 500 yeoman outside of Bloemfontein. The other commando units had similarly dispersed back to their home regions, only rearming when it was time to strike. In December an entire brigade was surrounded and shot to pieces by another Boer leader named Koos de la Ray. Other attacks flared up, seemingly everywhere the British were not present in force.
Supplies and communications were hamstrung at every turn, and seemingly no one was willing to tell the British who the remaining fighters were. By 1901, Christiaan De Wet had even snuck across the border and hit towns in the Cape Province, opening up another front in the war with the help of local Afrikaner guerillas. While the insurgency never gathered the momentum for a full scale uprising in Cape Colony, the possibility was never far from the minds of the British.
After three attempts to corner de Wet in the backveld failed, Kitchener took the gloves off. Always with an eye for the bigger picture, Kitchener began to work in a methodically draconian set of collective punishments for areas where the war was still smoldering. If a column was ambushed, Kitchener would burn the farms in the area where it happened, with the exception of any collaborators. While British thinking suggested this would force people to abandon the commandos, often as not it simply showed the Boers who their enemies in the community were. After the British passed they responded by burning any pro-British farms and killing anyone suspected of aiding the occupation. Massaging his temples, Kitchener then turned to one of the most iconic war crimes of the 20th Century for his solution.
Just two years before the Second Boer War, General Valeriano Weyler of Spain found himself in a similar situation to Kitchener. Faced with a large insurgency that relied heavily on civilian towns and farms for sustenance, the General opted for a policy of “reconcentration”, herding the local populace into specific areas. The idea had come out of his study of General William Tecumseh Sherman’s own brutal scorched earth campaign through Georgia in the American Civil War, and Weyler believed that it would allow him to sift the rebels out from the populace. In theory the camps were supposed to be well supplied. In practice, Weyler and his officers were both unprepared to feed 300,000 people, and in many cases exacerbated the situation through corruption and incompetence. Thousands had starved to death in the camps, and whatever military advantage they gave Weyler were overwhelmed by the political impact reconcentration had on United States attitudes towards the war.
While Kitchener could not claim to invent the term “concentration camp”, its popular use originates with his plan for the Boers, although historians continue to wonder if the result was born of horrible negligence or conscious brutality. Kitchener had several advantages over the hapless Weyler, the largest of which was that there was no power hungrily waiting for a chance to intervene on behalf of the Boers. South Africa was a long way from any power center, and Kitchener put this system to full work as he began to herd the populations of both former republics into a series of camps designated for both Boers and black Africans. This was counterinsurgency by centrifuge, spinning out the commandos from their families and safe havens by removing everyone who couldn’t run away in time. Even those who did flee with the Boer soldiers found Kitchener’s frightening thoroughness on display everywhere. Livestock were slaughtered, fields salted, and wells poisoned, and this was just to set the stage for Kitchener’s board sweeping conclusion.
 No colonial power is immune from this war crime. After successfully routing the Spanish the United States ironically turned to concentration camps themselves when faced with an ongoing revolution in the Philippines. One general termed the camps “the suburbs of hell”, with over 8,000 Filipinos dying from malnutrition and disease. The Germans would also resort to concentration camps and genocide in two wars in 1904 and 1908 against the Herero and Namaqua in modern day Namibia. And then there was the Belgian Congo of King Leopold.
 And lest anyone thinks the genocide of World War II shocked the remaining colonial powers into a more compassionate policy, then look no further than Britain’s policy in post-war Kenya. Even in 2015, it has taken multiple lawsuits to reveal the extent of the cover up conducted to hide massacres and internment of civilians by British soldiers.