I once worked for a man who spent most of WW II training to be a troop leader in the first wave to invade Japan. He and his fellows -- all volunteers -- expected to die in the first hour if they even made it ashore. He was a big fan of nuking Japan.
Anyway, my comment was not intended as a criticism but as an observation based on Russian military history and their conduct in the current invasion of Ukraine. Russia's large population traditionally meant that it could usually field large armies and overwhelm opponents -- as Napoleon and Hitler both learned. As Putin has found though, modern US and NATO smart weapons have changed the equation to the advantage of small, better equipped military forces.
My dad also trained to land in the first wave of Operation Olympic, part of Operation Downfall.
He was with the 33rd Infantry Division to land on Kyushu Island, expecting fierce opposition and massive casualties.
And they did actually land, just as planned, on August 28, 1945 and were met by, not the world's fiercest warriors with suicidal attacks, but rather by children carrying flowers to welcome them.
At some point after the landing they took a train to see the destruction at Hiroshima.
One key fact that most people miss is not just the savings in American military lives from the two A-bombs dropped, but rather the savings of many millions of Japanese civilian lives that Japan's military leaders were prepared to sacrifice to prevent American victory over their homeland.
In round numbers, those A-bombs are calculated to have saved about a million American military lives, including my dad's, plus up to 10 million Japanese civilian lives.
A similar event with similar consequences is unlikely to ever happen again.