Why did the us drop the atomic bombs on japan?

After pearl harbor was attacked.

The US decided to drop the Atomic Bomb on Japan after giving many warnings that the Japanese chose to ignore. While the amount of power and destruction with the new technology were largely unknown, it was thought that such destruction would bring a quick end to the 2nd World War.

However, we did drop the two bombs on two different days, which would have allowed the Japanese the opportunity to surrender after the first. If the first two bombs were not enough to force a surrender, several more were planned to be dropped in August and October.

Today, Japan considers over 400,000 people to have been affected by those two blasts, and has one of the toughest non-nuclear laws to this day.