There's an argument out there that the Soviet declaration of war on 8 August, and its subsequent attacks beginning early the next morning are what drove the Japanese to surrender. To that, I would respond by asking why the Soviets suddenly got off their butts, 2 days after the Hiroshima bombing, when they had spent the previous two years encouraging the Japanese to keep holding out for a less-than-unconditional surrender.
To be fair to Stalin, he had promised to declare war on Japan within 90 days of the German surrender and the Germans surrendered on May 8. Three months later Stalin's T34's rolled into Manchuko.
That said, I agree wholeheartedly with your assessment of Stalin and his motivations in 1945 but I just wanted to point out that, for what it is worth, he did honor the letter of his 90 day agreement.
As far as the British in the Pacific are concerned, the story of what was called the "British Pacific Fleet" is interesting:
By any standard other than comparison to the US Pacific Fleet, the BPF was humongous. It was arguably the most powerful fleet ever assembled by the RN consisting of:
- 4 BB's
- 6 CV's
- 15 CVE's and CVL's
- 11 CA and CL's
- innumerable DD's, DE's, subs support ships, and other smaller ships
I've read that most of the British Cabinet didn't want to send it because it would be so obviously a junior partner to the vastly larger US Fleet but Churchill overruled them because he felt it was important for Britain to contribute to the inevitable US victory in the Pacific.
The British carriers carried much smaller air-wings than their US counterparts but they were better defended against kamikaze attacks with their armored decks (US Carriers had unarmored decks and if you want to know why I'll explain the thinking behind it).
Back to the Russians:
I honestly don't know that Stalin's maneuvers accomplished much. The US was, of course, reading all of the Japanese communications back-and-forth with their ambassador in Moscow. When you read what Tokyo was saying, it is astounding. They were telling their ambassador to offer things that they had already lost to the US, as "carrots" to get the US to end the war. The Ambassador in Moscow had a clearer picture of reality and this put him in a difficult spot because he was being asked to try to negotiate something that was laughable on its face.
