There is a misconception in your question. While atomic bombs were dropped on the Japanese cities of Hiroshima and Nagasaki during World War II, they were not automatic bombs. These atomic weapons were specifically developed by the Manhattan Project, a highly classified research and development undertaking undertaken by the United States during World War II. The bombs dropped on Hiroshima (code-named "Little Boy") and Nagasaki (code-named "Fat Man") were manually operated and required a conscious decision to detonate them.