Some interesting scenarios.

(Assuming the allies beat the Germans without the US)

The Japanese/China situation would have been very different.

So the Japanese would not have been nuked and Australia and most of Asia would probably be under Japanese control.
No certainty about China because they're so many of them but I would suggest a lot of Chinese people would have been slaughtered by the Japanese.

The USSR would have gotten more of Europe... Maybe countries like Germany (all), Austria, Italy, Greece and Spain would have become part of the communist block and they would have had a lot more influence in the future of Europe.
Would have the US and USSR had their cold war? Yes but it would have been way more expensive and difficult. Even the UK could have become a communist country considering the influence Stalin had on their workers unions.

What would the US be like (today)?

Probably a semi socialist country with minimal influence in the world. You'd be isolated and looking inward.
You would not have had the mass immigration from Europe post WW2 and all of the good things that it brought to the US.
Canada would be very important to you along with Mexico and most of South America.

Peter, sure it is intriguing to speculate what if. But, if the US would have stayed neutral from the get go and not have supplied Great Brittain enormeously even before December 7, 1941, and if Japan would not have attacked Pearl Harbor, Great Brittain might have been forced to sue for peace with Hitler. The USSR, without British and American support, would have had a much toughter time to fight German forces. Then, maybe, Stalin and Hitler would have compromised and stopped somewhere east of Poland. Who knows, and then, why care? Things are the way they are. Let's look into the future and remembering the lessons from the past.

I agree with you but the OP posted this so I answered from that point of view.

That's a pretty big "IF". Even with the Russians at the other end I can't see how the allies would have won without US involvement.
The only way they could would be through absolute resolve and persistence. The war would have gone on much longer with a huge loss of life much greater than 50,000,000!

Everyone talks as if a Russian victory is a foregone conclusion, but without the 8th Air Force bombing German factories into oblivion from 1942 onward, without having to send massive reinforcements to fight the allies at Normandy, I think the Eastern front very easily could have swayed in favor of the Wehrmacht.

Let's not forget the Germans were on the brink of some cutting edge technology that would have turned the tide. Laser guided bombs, the Sturmgewehr, Gewehr 43, infrared sights, V1 and V2 rockets, Tiger II, ME-262, ME-264, etc. Without allied bombing and air superiority to beat the Germany industry down, these deadly weapons would have been much more prevalent and detrimental to the Red Army. There would not have been supply and ammo shortages. Who knows what other developments would have came to fruition without allied intervention. They would have had hundreds of thousands of extra bodies to send to the East including Erwin Rommel and a dozen Waffen-SS Divisions.

Its bad enough what those German and Jap SOBs did without speculating what further atrocities they could have performed given time.The world sure would have been a much worse place . Anyway the Germans are now talking of modifying their military policy to again include the possibility gf going on the attack in the future- they are still not trustworthy in any way.

I'm trying to imagine the Germans having another go
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No, I can't ;)

This.

SC, that just what they want you to go on thinking. They take no notice whatsoever
of conventions, eg, neutral countries are so much easier to invade, lets set up a looting industry, lets set up a killing industry, etc