Answer:
Atomic Bombs
Explanation:
Those cities were the place where the American Government conducted the Manhattan Project.
That project cost the government around $ 2 Billion with the purpose of creating mass destroying weapons that can turn the tide of war in one's favor. Eventually, it led to the creation of Atomic Bombs.
In the world war 2, US military dropped 2 of those atomic bombs, on the City of Hiroshima and Nagasaki In Japan. Killing around 146,000 people in Hiroshima and 80,000 people in Nagasaki.
This left the Japanese Government with no choice but to surrender, and make United States and its allies as the winner of world war 2.
