In my social circles I'm usually the first one pointing out the tiniest scent of anti-americanisms but this is too pathetic, even for me.
[1] https://en.wikipedia.org/wiki/Atomic_bombings_of_Hiroshima_a...
With all due respect to the enormous civilian suffering behind yours and the following numbers, why should there be an official excuse other than the obvious of winning the war against a barbaric enemy that had already ferociously invaded most of eastern Asia, the western Pacific and ruthlessly killed over 15 million people in the process?
The atomic bombings, by the perspective of the time and what had already been done, weren't even so terrible in terms of dead. The mass firebombing campaigns of the entire last couple years of the war against Japanese cities, using completely conventional weapons, had already killed possibly as many as 700,000 people with hardly any allied leader batting an eye, or the U.S. public for that matter. Given this mentality, and the subsequent lack of an apology for those conventional bombings, what would have made the atomic bombings deeply unique? (except for the nature of the bombs themselves).
Let's not also forget that Japan itself did everything possible to make the use of atomic bombs seem reasonable, having promised repeatedly that it would fight even in the face of horrendous casualties both for its own people and the forces of any invading army. Given the absolutist stance of Japanese forces in the field previous to those last weeks, fighting until every last man is dead and killing as many civilians as they could in the process, on directives and mentalities instilled directly from Tokyo, it's not hard to see why the Americans took seriously the idea of an unimaginable bloodbath in any potential invasion of the home islands.
Just look at the battles of Okinawa, in which the local forces encouraged their own local civilians to commit mass suicide as they lost the island, or the battle of Manilla, in which the knowingly losing Japanese just kept fighting, butchering, raping and burning the city solely for the sake of doing so.
Under the lack of foresight at the time, and given the nature of Japanese belligerence, it's not hard to understand why the U.S decided to drop the two atom bombs, given what they'd already done while still facing Japanese intransigence. Maybe it wasn't the most moral of choices, but under the circumstances, it had an understandable logic of hardened pragmatism that it's too easy to sweep under a rug of condemnation today with foresight, which itself might be mistaken even now.