Was the us justified in dropping the atomic bomb on japan ?

No

Explanation:

The dropping of the atomic bomb on Hiroshima was justified at the time as being moral in order to bring about a more rapid victory and prevent the deaths of more Americans. However, it was clearly not moral to use this weapon knowing that it would kill civilians and destroy the urban milieu.

No

Explanation:

It was immoral and cannot be justified based on just how many lives were lost and it was very reckless.

2018 means 2018 ce or common era

there have been other eras too including bce, which included way more years.