From the early 1950s, the USSR was the second largest contributor to the UN. Following UN rules, it gave much of its contribution in rubles, an infamously unconvertible currency that generally limited Soviet actions overseas. In the hands of UN officials, however, these ‘weak’ rubles became a powerful lever that made UN development projects more Soviet. Seeking to extract value from the ruble, officials increased the amount of UN development training held in the USSR, prioritized the purchase of Soviet equipment, and incentivized agencies to distribute Soviet manuals. Exploring the ruble lever contributes to our knowledge of the Soviet presence at the UN while foregrounding political economy as a key mechanism shaping UN practices more widely. Following the money in forms other than the dollar can reveal how economies of power at the UN intersect with global economic history, as well as the conceptual and contemporary challenges of international cooperation among wildly unequal economies.