Aforementioned article: http://www.filmsforaction.org/news/the_real_reason_america_used_nuclear_weapons_against_japan_it_was_not_to_end_the_war_or_save_lives/
The article doesn't strike me as particularly trust worthy, although it does bring up some questions about America's motivations (such as people suggesting that Japan would have surrendered soon anyways, so why would they have used two nuclear bombs as a means of forcing Japan to surrender?).
I was wondering if someone could shed a little more light onto this and/or refute any of the claims that the article makes.
There's always more to add on this, but there are quite a few items in the FAQ on this subject.
My primary answer would be that "America" didn't and can't have "motivations" for anything. That kind of language inappropriately confuses the issue. You should be searching out the specific people who made the call and what did they say before and after about it.