I think that it probably was assumed,

我認為當時可能存在一種設想

it certainly was always assumed at Los Alamos,

當然羅斯阿拉莫斯的人都這么想

that if the war were not over and not clearly to be brought to a conclusion by diplomatic means,

如果戰(zhàn)爭還沒有結束也沒有明確通過外交手段達成共識（結束戰(zhàn)爭）

this weapon would play a part.

這種武器就會上場。

At the time,

那時，

the alternative, the campaign of invasion, was much more terrible for everyone concerned

另一個解法，就是侵略日本本島的作戰(zhàn)計劃，對每個人來說要可怕得多。

I think that

我認為

Hiroshima was far more costly in life and suffering inhumane

廣島的事付出的生命代價，及承受的人道主義痛苦

than it needed to have been, to have been an effective argument for ending the war.

遠遠超過了的度，超過了它作為結束戰(zhàn)爭論據(jù)所需的程度。

This is easy to say after the fact.

事后說起來容易。