I imagine there ARE groups in the world that would love to pull off another 911-type attack and I'm sure they have their reasons.

I just mean that your logic and morals is terrible...
And tbh I don't think that the nuclear strikes was the MAIN reason for Japan surrending. As I understand military outcome after USSR start fighting in the Far East was clear for everyone. 

That's a poor analogy, really.  If Japan had the resources to respond (like the US did on 9/11), they would never have surrendered.  You're just using stupid major events as a shock tactic.

1. It was not an analogy, but a sarcasm. 

2. If you think that 'to respond' means 'to fuck up in Afganistan and Middle East' - then I understand your post. 
All that 9/11 thing looks very stupid. As a terroristic act itself, and as an answer to it also.

1. You're right, it wasn't an analogy, because it wasn't analogous, therefore the entire response was designed to try to piss someone off.  A feeble attempt at discussion.  So was the ad-hominem you resorted to later in your conversation.

2. Afghanistan and the Middle East were already fucked up, they just fucked it up worse.  But, Afghanistan made their choice.  They could've just handed over the Taliban.

What a coincidence, neither do I.

It was pretty clear to everyone after the Allies took Okinawa which itself had followed a string of Allied victories in the Pacific long before any Soviet intervention.

It sucks, Pearl Harbor sucks, wars suck in general. That's why they are best avoided for a civilization. Something is really wrong with a civilization that goes to war.

It did, they say, help bring about a quicker end to the war. As I understand, Japan thought they would have to fight this war for 100 years and think about how many more people would have died or suffer. The propaganda on each side being evil baby eaters was disgusting - but that is what happens in war (each side wants to be the 'good guy.') It was so sever that unknown many committed suicide rather than be captured such Suicide Cliff in Saipan. https://en.wikipedia.org/wiki/Suicide_Cliff

Kind of like the current propaganda campaigns to vilify and dehumanize people of the Middle East, Islam, Gays, Gingers, and the Left Handed.

Basically it was awful, but that's part of war. And why we should always try to prevent and avoid war.

Since you cut the interesting part of my reply, I'll ask, again:

What happened to the country that cared so much about civilian deaths? It didn't take long for USA to support military coup d'etats that overthrown democratic governments (with obvious consequences to civilians opposed to them), do napalm bombing, agent orange or support terrorists like the contras.

If they really believed it was necessary, they could have at least limited innocent civilian casualties choosing different objectives. And considered long term damages. But hey, radiation damage was already known since the first years of X-rays medical use, but American and Russian general staff kept on killing countless people with the rubbish left by their nuclear experiments for decennia after the end of WW II before finally yielding to the evidence.

Your question is a complex one but I'll try to keep my answer brief. Feel free to ask more if you feel it necessary and I'll try to answer to the best of my ability.

I'm going to say a change of US leadership with different administrations exercising varying degrees of restraint in their actions happened. As an example, Lyndon B Johnson forbade bombing certain targets in North Vietnam. Richard Nixon, the man following Johnson was not so inhibited going so far as to even bomb parts of Cambodia. Congress funded the Vietnam War during the aforementioned two administrations but during President Ford's term, Congress wanted no more of the Vietnam War and refused to provide any further military spending on South Vietnam. President Ford himself had the honor to declare the Vietnam War over "as far as America [was] concerned" as North invaded the South.

Civilian casualties certainly matter but depending on who is in office, they will matter to varying degrees.