 Throughout World War II Sambuu played a key role in funneling Mongolian monetary and material assistance to the Soviet Red Army fighting German troops.He also took a keen interest in supporting Mongolian students (including future leader Yumjaagiin Tsedenbal) who were studying in Russia, seeing them as the key to Mongolia's future, and cultivated many of Mongolia's future diplomats.However, Sambuu was also his country's chief diplomatic representative during the Stalinist repressions in Mongolia during which several of Mongolia's top leaders were arrested, transported to the Soviet Union, and executed, many at the Butovo firing range just outside Moscow.