Not every chance. A small reduction in probability. The key word in my argument that you're not addressing is that they made a tradeoff.
The probability was small in the first place, so throwing it away was a small reduction in probability. But there was no chance at all that Germany would conquer all of the Soviet Union in one step. Especially while fighting inefficiently, also fighting in the west and distracting themselves with other things.
And throwing one thing away to pursue another is a tradeoff. I just pointed out one tradeoff that they made, wich I consider inconsistent (for the reason stated in the grandparent of this comment).
We started out by considering their success in terms of their own goals and under the assumption they were being rational.
Consider it under their goals: Of bloody course. Assume that they were rational: That's exactly what I was arguing that they weren't. It doesn't make any more sense to assume one side of the argument than the other.
assume ... that they didn't believe in their stated anti-Jewish goals at first ...
I'll expand a bit on that if you don't mind. There were two (sets of) reasons why they hated the jews.
*1) Their biological beliefs, where the jewish race and the aryan race were "natural enemies", and the aryan race could be diluted by the jewish but not vice versa. For that reason they wanted to get jews out of every significant part of society, and prevent them from crossbreeding. That goal could be pursued by genocide, or by isolating jews in ghettos and keeping others from associating with them. The nazis did the latter successfully in every place that they controlled before they started on the final solution. Jewish leaders were quite willing to cooperate with the nazis in this matter, because they got more power in the ghettos than they had in the outside society.
Isolating and concentrating jews was probably a necessary stage before extermination. And once that was achieved the jews were not a significant threat (even from the race biologist perspective). People very seldom revolt purely because of bad conditions. They revolt against change, of which there is very little in a ghetto. And while they were kept around they were an economic asset. But once you upset the boat by starting the killing you risk getting revolts. As they did in several places.
*2) They wanted an outgroup to spread hate and fear against. And the jews came in handy, again for two reasons. First the nazis already wanted to hurt jews because of 1). Second it was easy to rile the germans up against jews due to widespread christian antisemitism. For that reason they did a lot of antijewish propaganda (as you referred to earlier), some related to 1) and some being pure lies and fallacies. It also meant that they had to give the appearance of a continued campaign against the jews rather than just doing the minimal to solve the problem in 1). But spending one bullet or one drop of fuel beyond what was needed to appear credible for the proles for the purpose of 2) was irrational.
But since the nazis kept talking and thinking about the propaganda in 2) as their reason for their actions in 1) they felt that they had an urgent need to continue with the genocide. Even when that hurt their original goals.
But there was no chance at all that Germany would conquer all of the Soviet Union in one step.
According to most of the historical analyses I've read, Germany certainly might have defeated the USSR conclusively - if they hadn't made mistakes like the 6th Army not retreating from Stalingrad, and if they had succeeded in conquering Murmansk, and if the USA had not started to provide huge amounts of aid to the USSR. They did have a lot of luck - more than might be expected - but it certainly wasn't impossible for them to have a bit more luck and win outrigh...
As Eliezer and many others on Less Wrong have said, the way the human species rose to dominate the Earth was through our intelligence- and not through our muscle power, biochemical weapons, or superior resistance to environmental hazards. Given our overwhelming power over other species, and the fact that many former top predators are now extinct or endangered, we should readily accept that general intelligence is a game-changing power on the species level.
Similarly, one of the key ingredients in the birth of the modern era was the discovery of science, and its counterpart, the discovery of the art of Traditional Rationality. Armed with these, the nations of Western Europe managed to dominate the entire rest of the world, even though, when they began their explorations in the 15th century, the Chinese were more advanced in many respects. Given how Western Europe, and the cultures derived from it, has so completely surpassed the rest of the world in terms of wealth and military might, we should readily accept that science and rationality is a game-changing power on the civilization level.
However, neither of these imply that intelligence, science, and rationality, as a practical matter, are the best way to get things done by individual people operating in the year 2009. We can easily see that many things which work on the species level, or the civilization level, do not work for individuals and small groups. For instance, until the discovery of nuclear weapons, armed conflict was often a primary means of settling disputes between nation-states. However, if you tried to settle your dispute with your neighbor, or your company's dispute with its competitor, using armed force, it would achieve nothing except getting you thrown in prison.
People are crazy and the world is mad, but it does not necessarily follow that we should try to solve our own problems primarily by becoming more sane. Plenty of people achieve many of their goals despite being completely nuts. Adolf Hitler, for example, achieved a large fraction of his (extremely ambitious!) goals, despite having numerous beliefs that most of us would recognize as making no sense whatsoever.
We know, as a matter of historical fact, that Adolf Hitler and his Nazi Party, despite being generally incompetent, unintelligent, irrational, superstitious and just plain insane, managed to take over a country of tens of millions of people from nothing, in the span of fifteen years. So far as I am aware, no group of people has managed to achieve anything even remotely similar using, not only rationality, but any skill involving deliberative thought, as opposed to skills such as yelling at huge crowds of people. However, it is a corollary to the statement that no one knows what science doesn't know that no one knows what history doesn't know, so it is entirely possible, perhaps likely, that there is something I am overlooking. To anyone who would assert that intelligence, science or rationality is the Ultimate Power, not just on the level of a species or civilization, but on the level of an individual or small group, let them show that their belief is based in reality.