The thing is, the moment Germany attacked the Soviets, there was never going to be a peace treaty until one or the other was defeated. No more than a peace treaty was possible between the US and Japan in that war.
Germany could have made peace treaties with the UK and US. However, all of the Allied Powers had agreed to no separate peace deals, and the war became an all or nothing affair. The only nation that 100% burned all peace deals with the allies was Japan. By simultaneously attacking the US and UK and their brutal behavior there was no way either of those countries would have accepted any kind of peace deal short of their defeat.
People tend to forget that the Japanese were brutal occupiers. Massacres and war crimes were all to common, especially against the Europeans captured. Tens of thousands killed in mass executions, women forced into prostitution in government brothels, Starvation and torture were common facts of life for even civilians held prisoner by Japan. This can be seen clearly in Eric Liddell, who was later one of the main characters in the award winning movie "Chariots of Fire". A Scottish missionary who had been in China as part of a mission, he was interned by the Japanese in 1941 and died in 1945. Primarily from starvation and poor health because of his captivity. And in 1924 he had won a gold medal at the Olympics.
But war between the US and Germany was coming. Much as it was in WWI even before the Zimmerman Telegram. Increased aggression towards neutral US shipping, and actually firing on ships in out territorial waters was already pushing the two sides towards war. And this can be seen in the US because they returned to conscription in the Summer of 1940. Well over a year before they entered the war. Of course, then they were expecting one from Germany, not Japan.
The accepted belief among most was that the US would enter that war because of Germany, and that Japan would then jump in afterwards. Not what actually happened, which was the reverse.