K first off I just could not see a way that if WW1 ends as in our time it does not end in some form of WW2. Frankly if mother Theresa and every saint in heaven was in charge of Germany after the great war there still would have been a second world war. It was recognised at the time by all the statesmen concerned and it is recognised now. I am no cleverer than those politicians then ,even with the benefit of hind sight.
So I followed the letter of the POD rather than the spirit

and my time line does begin after the end of WW1 albeit with a smashing defeat and a vengful rather than punitive enforced peace
I thought long and hard about communism and how to stop the sparticists from taking over .With this in mind I gave Russia a long, bitterly contested civil war . The soviets have their hands full at the moment and have little time to help The comintern may be an idea in the back of Lenins mind [If he's still alive] but it will have to wait until/if victory is achieved.
Next I put famine in Germany, it's difficult to think of, let alone plan political change if most of your day is spent wondering where your next meal is coming from .Not impossible I agree, but much more difficult.
Next blow against communism is the massive dislocation that happens ,Germany is full of displaced persons and rampaging vengeful armies with the destruction of Paris in their minds .Something along the lines of the thirty years war and Po Pots year zero is begining in Germany.
There will be a resistance movement in Germany and it may well be led by the communists but that is all. Besides the allies have seen what communist revolution can do in Russia ,they are likely to come down hard on any signs of it in Germany.
With Germany turned into an agrarian society there is no upturn in German industry which was one factor in the crash of 1929. France, Belgium etc are devasted and will be reliant on US goods to rebuild for a good number of years, even if they still had the money and resources left they simply dont have enough man power left after 6 years of bloody war.
Next the UK embraces Imperial preference, reducing its reliance on imports from the US
Both these factors will mitigate any sudden changes in the finacial markets.There will be a slowdown, and it will hurt but not to the degree it did IOTL.
Next Japan is co-opted into an economic union which recognises it as a full blown member of the club of victorious nations and recognises its 'special interest' in China . this not only disempowers the more rabid nationlists in Tokyo, but allows a swifter absorbsion of China with the UK [six years of war hav'nt been helpful to the UK economy which needs a massive cash injection.. and China is a rich undeveloped country

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So with Germany 'gone', Russia divided, Japan on side and the USA contemplating its navel all the major players of WW2 are changed
Europe will be licking its wounds for a while yet but won't have to worry about a resurgent Germany.
There will be changes
No family planning and no abortion, in fact taxation will be skewed to favour large families
Political parties will favour mild pacificm or massive rearmenent ,unionism will follow these lines with for example the skilled trades which have a vested interest in arms manufacture favouring the latter. this slows down the growth of socialism as it has less support amongst the working classes.
Eugenics will become popular 'to improve man so that war is bred out of us'.
Air travel becomes less of a novelty earlier due to two extra years of ariel warfare pushing development
Entrenepuership is encouraged especially in the far east with China touted as the 'new India'
No Washington treaty, Japan is backed by the UK in the negotiations
Holland faced by competition in its far east empire from the co -prosperity sphere joins as a junior member further alianating it from France .
Poland enacts laws against refugee Germans forcing them to live in 'areas of special control'