The new technology was at the time considered a "gadget" by the US military was the atomic bomb and its weaknesses were its high cost and required labor.
The atomic bomb was initially considered a gadget since it was the countermeasure to a supposed atomic weapon that was being created by the Nazi forces, with which they should represent an attack of the same magnitude as that created by the enemy.
However, after the events of Pearl Harbor, the bomb was used in Hiroshima and Nagasaki, causing the surrender of the Japanese army but representing an expense of 2 billion dollars each, as well as a team of 125,000 workers in its construction.
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