William C. Bullitt
William Christian Bullitt Jr. (January 25, 1891 – February 15, 1967) was an American diplomat, journalist, and novelist. He is known for his special mission to negotiate with Lenin on behalf of the Paris Peace Conference, often recalled as a missed opportunity to normalize relations with the Bolsheviks. He was also the first U.S. ambassador to the Soviet Union and the U.S. ambassador to France during World War II. In his youth, he was considered a radical, but he later became an outspoken anticommunist.
Source: Wikipedia