How was the dropping of the atomic bomb in japan courageous?

Well for starters it showed a determination by the US to win this battle and no sacrifice troops. It showed its power to the world knowing that Russia could have shown its power. It wasn't even sure if Japan was going to surrender... All of these should do.. Pick and choose

the china one is last

explanation:

roosevelt believed that in light of the country's recent military successes, it was unnecessary to use force to achieve foreign policy goals, so long as the military could threaten force. this belief, and his strategy of “speaking softly and carrying a big stick,” shaped much of roosevelt's foreign policy.