"General" Finley,
The smart thing? Attacking the USSR was the smart thing for Japan to do? The same USSR who had done
this to Japan's vaunted Kwantung Army in the summer of 1939?
Here's a snip for those who don't want to follow the link:
By August 31, 1939 the Japanese had been driven back out of the disputed territory. Of 60,000 Japanese troops committed, nearly 45,000 were killed. The IJA 23rd Infantry Division took 73% casualties. The 71st Regiment suffered over 93% losses. In contrast, the IJA took 28% casualties at Mukden, the most hard fought battle of the Russo-Japanese War.
So in the summer of 1941 with the same tactics, tanks, artillery, and aircraft, the Japanese are going to go for Round Two with the same enemy who kicked their asses so thoroughly just two years before?
And what will such an offensive do for Japan? She's bogged down in China and she's already under embargoes from the US and Europe. How will expending more oil, more ammo, and more lives fighting over the essentially empty Trans-Baikal region going to help her one whit? (Please don't bring up the oil in Siberia. Given the technology of the period, Japan could neither find or exploit it.)
No. Myths aside very few troops were redeployed from the USSR's Far East to fight the Germans.
With the addition of this useless Japanese attack? No.
Yes. Japan is still going to launch the "Lunge to the South". In fact, in fighting the USSR, Japan needs to capture the Southern Resource Area even more urgently.
No. That's still ASB given your changes.
The Pacific War may very well be shorter with more of the Japanese Army killed in Manchuria earlier on and the logistical demands for the front there straining Japan's industries even further. Japan will be more stretched more earlier. Something will have to give, perhaps a draw down of fighting in China or a defensive posture in Burma sooner.
Bill