The aim(s) of this timeline:
- The conflict called "World War II" has to end in Europe and nearby areas (Caucasus, Near and Middle East, Northern Africa, Iceland/Greenland) until silvester 1945, max. (A permanent armistice as between the two Koreas would count.)
- Nazi Germany and its allies in Europe and nearby (see above) have to have ceased warring with the US, the British Empire, and the Soviet Union, or never started to make war with them in the first place. Or vice versa.
- Nazi Germany and its allies have to control de facto all of the Soviet Union's territory west of the Dniepr and south of the Düna/Dvina river. Minimum.
- The western Allies (US, Empire, Free France) must not have a foothold on the European continent, save for Gibraltar maybe.
(After thinking this over:)
- The Reich also should control all of North Africa from Morocco to the Suez Canal, to make a US-lead invasion harder.
- The Reich has to control enough sources for crude oil: In the long run, Algeria and Libya would work too, but even in the short term, the oil from Romania and lesser sources won't be enough, neither will fuel produced from coal. If they don't conquer the Caucasian oil, the closest source would be nothern Iraq. Either would work - as would be long-term good relations to a source of crude oil.
- Of course, all islands in the Mediterranian (Malta, Cyprus) have to be under control as well. Gibraltar preferably as well.
- Nazi Germany has to survive in recognizable shape at least twenty years after World War 2 ends. Meaning:
- The head of state has to use the title of "Führer".
- It has to be a one-party state effectively ("block parties" as in Communist Eastern Europe would pass, though), governed by the NSDAP.
- Said party's ideology has to include German(ic) über nationalism, aggressive militarism, expansionism, white supremacy (even if called differently), and radical antisemitism. In theory and practice.
- It has to control (together with allies and satellites) at least the same territory it controlled when the World War ended. Losses are acceptable only if it gained more and better territory in some other place before said losses happen.
- Adolf Nazi, if dead after those twenty years, still has to be held in high regard officially. No "Dehitlerization" (like Destalinisation) allowed.
- Almost superfluous to say: It has to be settled mostly by German-speaking citizens of Germany. Humans, not robots or zombies. Who actually mostly have German(ic) ancestors.
- Most important: Only realizable events. No FDR/Churchill suddenly becoming convinced to become a nazi and make his country join Germany's side (that's against the laws of human psychology). No sudden invention of genetic engineering or artificial intelligence way ahead of their time (that's against the laws of scientific progress). No Maus for every German soldier (that's against the laws of production). No transports of a million men over 1000 miles in a day (that's against the laws of logistics). No discovery of yuge oil fields under German soil (that's against the laws of geology).
Additional: Adolf Nazi has to be alive, not comatose, not incapacitated, not committed etc. In short: To be able to give commands to people and notice at least when they aren't executed.