In a London office in the late 1940s, a map of East Africa was spread across a table and treated as a promise.

Britain had won the war but was still rationing cooking fat. Officials believed they had a simple answer. Clear millions of acres of Tanganyikan bush, plant groundnuts by machine, and ship the oil home. The plan grew to 3.21 million acres, divided into 107 mechanical units, and its confidence rested on one idea: a state that could organise a war could surely organise a harvest.

Then the plan met the ground. At Kongwa, the largest site, roughly 11,000 African workers were employed by 1949, working beside a European management staff to clear ground that fought back. Machines broke down faster than they could be repaired. Rainfall estimates had been borrowed from a wetter district nearby. Clearing costs climbed, harvests disappointed, and the numbers that mattered most were the ones nobody wanted to report.

In 1951, after more than £30 million had been spent, the scheme was abandoned. In Britain it became a joke about government extravagance. In Tanganyika it left roads, workshops, and communities whose lives had been bent around a project that was never going to deliver what it promised.

The Peanut Plan tells the story of one of the most costly failures of late colonial planning, from the ministers who believed in it to the people who cleared the land and lived with the consequences. It asks how so much money, machinery, and political backing could be committed before anyone had tested whether the idea would work.

The harvest never came. The assumptions behind it lasted much longer