The statement is overly simplistic and can be misleading. The atomic bombings of Hiroshima and Nagasaki in August 1945 were complex military decisions influenced by various factors, including the desire to bring a swift end to World War II, the hope of avoiding a costly invasion of Japan, and the demonstration of power in the context of post-war geopolitics, particularly regarding the Soviet Union.
While there were certainly concerns about Japan's resilience and the potential for prolonged conflict, the primary motive for the bombings was not fear of Japan but rather a desire to hasten the end of the war and minimize American casualties. Thus, it would be more accurate to say that the bombings were a calculated military strategy rather than a reaction driven by fear.