Japan has been an ally of the USA for a long time now.
On the other hand, every year they observe Hiroshima Day.
Moreover, Japanese people visit Yasukuni Shrine.
Then what is the catch?
The effects of Hiroshima and Nagasaki run quite deeply. One of the most profound effects is that Japan is very pacifistic and one of the few (if not the only country) that has outlawed war. Article 9 of the Japanese constitution prohibits the Japanese government from declaring war, although permits Japan to maintain a self-defense force. Since the end of WWII Japan's conditions of surrender and reliance on American markets has forced it to maintain US military bases which are widely disliked, especially in Okinawa where there have been numerous demonstrations against the American presence there (Blowback by Chalmers Johnson provides a very detailed analysis of Japanese concerns with US military presence).
Being the only country that had been the target of nuclear weapons, Japan also is very much against the development of nuclear weapons. One of the conditions of American forces being deployed in Japan is that nuclear weapons not be deployed on Japanese soil, and Japan has been stridently against weaponizing their nuclear program. Unfortunately, the American military establishment routinely mocks this requirement by having nuclear weapons deployed on naval craft stationed "in transit" in Japanese waters.
In essence, the relationship between Japan and America in the last 60 years has been complex. Japan's quick growth has been heavily reliant on preferential access to American markets and technology (to an extent where the US has been willing to harm its own balance of trade and allow Japanese firms to co-opt American companies trade secrets). In return the Japanese political establishment has allowed American forces to be stationed in Okinawa indefinitely. While this benefits most of Japan, Okinawa has had to surrender the best 20% of its land and has received the least of the benefits of Japan's growth. The Okinawans have thus been the most vocal opponents of the American military presence.
TO SUM: The benefits of America bending over backwards to provide favorable trading terms for Japan, and the ability of the Japanese to exploit this, has lead to a more prosperous Japan. These developments have generally overshadowed not only the past animosity over the war and nuclear bombings, but much of the tensions that arise between American militarism and Japanese pacifism as well. (The exception being in Okinawa of course).
On the one hand US people observe Columbus Day every year. On the other, the US have discriminatory practices in favor of Native Americans ("affirmative action"). These two phenomena are not irreconcilable.
You can honor and celebrate some things that Columbus did (e.g. "discovery" of America) without approving everything he ever did (e.g. lead to genocide of Native Americans).
Likewise you can honor and celebrate some things done by some of the people commemorated at Yasukuni Shrine (according to Wikipedia, Yasukuni lists the names of some 2,466,532 men, women and children), without approving every single thing that anyone commemorated at Yasukuni ever did.
About the Yasukuni Shrine part of the question, since no one has addressed that:
It is important to remember the nature of that establishment. The Yasukuni Shrine houses over 2.4 million of Japan's war dead, only 0.043% of whom (1,068) are convicted of any war crimes. They weren't even all members of the Japanese military. Those commemorated at the shrine include the shihi of the Meiji Ishin, diplomats, nurses, war factory labourers, sailors of the Japanese merchant marine, and hundreds of schoolchildren who perished during the sinking of transport ship Tsuhima Maru.
Traditionally, Japanese culture holds that all sins are absolved in death. This and the fact that 99.9% of everyone listed aren't war criminals make visiting the Yasukuni Shrine a non-issue as far as Japan's current pacifism is concerned. Japanese domestic objection to visiting the shrine is mostly because "it upsets our neighbours."
As for the atomic bombings themselves, first and foremost Japanese society holds Hiroshima and Nagasaki up as the epitome of the suffering and destruction that war brings. Many Japanese may feel it was unnecessary for Japan's surrender (being, perhaps, better acquainted with the efforts of the Japanese doves to seek peace than Western depictions of a singularly fanatical militant race may inspire). At the same time, most are not particularly upset with America over it. Many leading Japanese have made remarks to the effect that "this sort of thing happens when you start a war."
Instead, the atomic bombings largely feed into Japan's national psyche, which consider the Japanese people a victim of the war started by their jingoistic, reckless leaders (compare and contrast with Germans). Justified or not, the uniqueness of Japan's position as the only country to suffer an atomic bombing is often stressed, underscoring Japan's perception that it experienced some sort of special victimhood.
The days are coming to close for the heroes of WWII. Most are now in their 80's and 90's; the rest are gone. Heroism is relative term, because heroes exist on any side of any conflict. It's defined by one's convictions and resultant actions, and history becomes their judge.
I had the fortunate experience of living in Japan from 1969-1971. My father was FAW-6, stationed at MCAS Iwakuni. The officers were encouraged to hire local women as housekeepers to help out the local economy. And thus began my relationship Kazuko Kawaguchi and her family. Her husband was a civil servant employed by the base. It was not long before I was more or less adopted. Shortly after THAT, I met Ojisan (Grandfather). He had been an infantry officer 25 years earlier, and he still had his binoculars from that period. He had retired to a small farm intent on growing rice and legumes, and we spent a lot of time sorting those beans in a reed tray. He spoke no English, and I precious little Japanese; but still a bond was formed. When we had the benefit of Kazuko, or Takenobu, (his son, Kazuko's husband), he would tell me tales of Samurai, Bushido, and his family's long, proud history. On occasion, he would mention the war, and a few details. When he did so, the rice wine would manifest misty eyes, a halting voice, and a far away look. Through translation, I was able to put together some of what happened, the friends he had lost, and a few of the assignments he had had; but, always afterwards, he would look at me, mess up my hair, and smile. Even though I was a descendant of his enemy, he opened his home, offered his friendship, and shared his life and experiences.
It's been my experience that hate is really an inefficient and destructive thing. As a 13-year vet, in a different theater and campaign, actions fuelled by hate usually go awry. It's also been my experience that the Japanese have managed to come to terms with the most horrific attack conceived by man to date.
Regardless of the opinion you may hold, (pro or con), on the bombing, it happened. There was a terrible loss of life, and according to whichever article or report you believe, two thirds of those killed directly, or indirectly, were civilians, and 20,000 were esitmated to be military. Now, 69 years later, Japan's economy is inextricably linked with ours, tourism is on the rise, and still, we are haunted by images of the hellish aftermath Photos of a barren landscape, seared bodies, the shadows of those vaporized, (the fortunate ones), and the iconic Genboku Hall, (the famous dome building of Hiroshima). Let us hope that those images serve to remind us that a nuclear strike should be a monumental and weighty decision.
As the child of a man who was scheduled to be part of an invasion force of mainland Japan, and given the casualty estimates for that activity, it is likely in the extreme that I personally, and my children, as well as my sibs and their children, would not have existed if not for Hiroshima/Nagasaki.
From this standpoint, how can anyone reasonably condemn me for saying that I am thankful for the bombings?
Hiroshima and Nagasacki, terrible as they were, likely let my family exist.
Japan was the aggressor in WWII. This is a matter of record. Japan was further loathe to surrender in 1945.
Therefore, the moral burden for the bombings rests entirely on Japan.
I know that many Japanese are resentful of this perspective, though the perspective that the bombs were necessary and that that necessity was imposed by Japan is hard to argue with in any sort of rational way.
Could we be sure the Japanese would surrender without the awful hammer of the bomb?
Most historians think the answer to that question is "NO".
More to the point, most historians opine that the Japanese would have kept fighting if the Allies did not end the pacific war decisively.
So in the use the bomb side we have 1. Japan started the Pacific war with a sneak attack. 2. The Japanese had comported themselves as brutal fanatics throughout the Pacific war. 3. We could deal a knockout blow with the bombs, if we used the bombs before any other power developed or stole them.
On the don't use the bomb side we have: 1. They started the war, and if their military was not removed, would continue it. 2. It was the bomb, or an invasion, with aforementied devastating causualties for the Allies AND JAPAN.
Looks like the case for using the bomb was strong.
Remember,Japan was actively seeking their own bomb.
Thank God we got the bomb first.
Truman would have committed treason had he chosen not to use the bomb and invade.
The lesson of WWII Japan is that no country should ever allow a military dictatorship to take it over, even if you have to fight a civil war to stop it.
Military dictators may turn your country into an enemy of global peace (as Japan was in the early 1940s), In that case, the world is not to be blamed for whatever it has to do to put an end to your depridations.
The bomb assured that persons far more responsible than the allies (specifically, the military and political leadership of, as well as the populace of, the Asian Axis power, Japan) paid for starting the war in the Pacific, not third parties (Allied soldiers and their families).
No other outcome would be moral.
Yes, the A-bombs were terrible things.
May no human population ever feel treatened to the extremity of nuclear weapon use ever again.
More importantly, may no human population ever again be such a grave threat to world peace that the use of these terrible weapons seems necessary or rational.
While wating for a Japanese perspective here, here's an American's.
They do still seem to be a wee bit sore about the whole thing. I've noticed it appears to be a popular belief among the Japanese that the bombings were unnesscary. Whatever your opinion about this as a historical theory (a topic for another question, please), it does happen to be the position you'd need to take if you were in their shoes and wanted to be upset with the USA over it.
Note this goes both ways though. Our WWII generation is dying off now, but they've been the opinion setters for quite a while in this country. Being an ally with the same folks who slaughtered your brothers in Guadalcanal isn't easy.
At this point it seems to me the A-bombings are kind of like having a political difference with a cousin that you have to eat dinner with on holidays. We both know its there, but peace in the family is important, so both sides try very hard to avoid the topic.
It probably helps a lot that Japanese culture favors being very oblique about difficult topics, while USA culture is so blunt that such sublteties are generally lost on us. For example, ever seen a Japanese monster movie? You know the ones where some kind of nuclear thing (usually done by the USA) creates a gaint monster that destroys Japanese cities? Guess what those are really about. Its probably rather disturbing to the Japanese how much we in the USA enjoy them.