Just to add my thoughts on the political setting of a post-war Germany.
The talk about whether Germany will get a "Nazi"-government some decades after a WW3-conflict is probably confused by the fact that different people apply the Nazi-label to different things. To clarify my understanding, to me a Nazi-government would be
- anti-democratic (wanting to abolish elections, Führerprinzip and what not)
- anti-free market (forced cartels of national industries, four years plans etc)
- militaristic (arms build-up etc)
- revanchistic/imperialistic (wanting to claim or re-claim territory of neighboring countries)
- nationalistic (beginning at expelling and going up to the extreme point of committing mass murder on non-natives)
While I could easily see a post-war Germany being a lot less pacifistic and even somewhat vengeful against Soviet Russia, I can hardly see any major reasons for Germany to abandon democracy, the current free market structure or being less foreigner-friendly - in this scenario, the Bundesrepublik survives because of the commitment of its NATO allies, and victory - even a bitter one - would be seen as a validation of the current system. That there following a WW3 would be a demand for an Anschluss with Austria or reclaiming Suedetenland just seems without any basis in reality and more like the Soviet revival scene from the Simpsons (as seen here:
)
Still, this is a war-torn and poorer country, but likely the intuitive response of the German leadership would be to double down on securing stability/continuity (i.e. Grand coalitions) and European integration with France and the EU, so maybe the treaty of Lisbon comes a decade earlier.
Across Europe, the economic downturn, possibly combined an accelerated European integration would likely lead to the rise of populist anti-establishment parties like in the '10 already in the 1990', but likely this will not only be a mix of simple positioning ala Macron or 5 star movement, post-communism ala Podemos or German Greens or nationalism like AfD or Front national. The hard left would probably take a beating in the first elections, but would likely spring back as post-communistic parties (by this, I mean parties that essentially have a political platform calling for all the typical socialistic items, but keenly avoids ever calling itself socialist in any way).
On the global scene, you would likely have a Europe and a Soviet Union looking a lot more inward, meaning simultaneously a bit more local chaos and more Pax Americana.