Final answer:
Britain struggled to defeat the Boer farmers due to the Boers' guerrilla warfare tactics, knowledge of the local terrain, motivation to protect their land and resources, and the smaller size and preparedness of the British army.
Step-by-step explanation:
Several factors explain why Britain found it difficult to subdue a relatively small number of Boer farmers during the Boer Wars. The Boers were adept at guerrilla warfare, which was a stark contrast to the British army's conventional warfare tactics. The rough terrain of South Africa favored the Boers, who were familiar with the land, while the British forces were not. Additionally, the Boers' strong motivation to maintain control over their land and resources, particularly after the discovery of diamonds and gold, galvanized their resistance. Furthermore, the British army, focused primarily on its naval strength, was relatively small, and the use of volunteer troops may have affected the efficiency and readiness of the British forces. The scorched-earth policy adopted by the British, aimed at denying shelter and food to the Boers by destroying farms and relocating women and children into concentration camps, also drew international criticism and did not significantly quicken the British victory.