The image of President Obama, the first US president to visit the site where the nuclear age was unleashed, embracing the survivor of the Hiroshima bombing, marks a moment of an extraordinary acknowledgement of the enormity of nuclear weapons' use--without constituting an apology.
What president now living could apologize for an act which caused such casualties? How would we or could we place such an event in its historical perspective and re-litigate why it ever took place? It is not possible to entirely do so, but the correct approach is what Obama has done--acknowledge what happened, and point to a task to prevent the use of these devastating weapons from ever happening again.
This does not stop his insane detractors on the right, of course, who ignorantly decry an "apology tour" that has not ever happened in the course of Obama's presidency. What such ignorami reveal is a disgraceful inability to respect the idea of soft or even smart power--a total lack of appreciation for the very idea of diplomacy at all, or an understanding that the place of the US as first among nations and its standing and respect must flow from our adherence to some standard of decency. That we ought not torture, or detain without charge, or go to war without valid interest, or commit atrocities abroad should be a matter of our highest interest--on which our national reputation rests. That we reject nuclear attack or the idea of "total war" is a matter of principle.
It would be great if both parties understood this intimately and did not play the unattractive game of calling out our President as somehow being Un-American for trying to do what is fundamentally decent. But this is not how it is. This is not how it is at all.
The current GOP Presidential candidate is in favor of nuclear proliferation and torture, and has the full support of his party, with only some tepid reservations expressed by useless dupes who think the real problem with their guy is his "tone".
This image above is what America should be--big enough and strong enough to embrace the history we have made. I am sorry, myself--sorry that so many Americans are so very, very small.