That is one very unusual idea. So in the war which was conducted by all major powers in the word with hundreds of millions in population and multimillion armies it was a relatively small group of people with no nation of their own, speaking different languages, and, as diverse as 18 million people could be, with only one thing in common – religion and culture actually defeated Hitler.
This idea seems to be a preposterous until one think about perception of the war by Hitler and all other ideological Nazis. In their minds it was the war of races between superior and noble Arian race and filthy, disgusting, and evil race of Jews. It is weird, but it was not only in their speeches and writings where ideological Nazis expressed opinion about enemies they are fighting, but even more important this opinion directed their actions. Even during the most important moments of battle when everything was on the line, the Nazi leadership gave priority to trains carrying Jewish children to gas chambers over trains carrying ammunition for German troops on the front line. If this is truth, then in minds of Nazis these children were more dangerous enemy then Russian or American soldiers. And at the final count by this logic with Hitler and Nazis going down in April 1945 while 12 million of world Jews out of 18 million before WWII of world and 3.5m out of 9.5m European Jews still alive, Nazis were defeated in this race war.
In reality it was not really war of races. It was ideological war of the world including Western democracies of America and Great Britain, International socialism of Soviet Union, and everything in between against German National-Socialism. The inequality of resources was so significant, that Hitler could not possibly win even if ammunitions were put ahead of killing children.
Nevertheless this book provides a good overview of totality of efforts of individual Jews and their influence on outcome of this struggle:
1. Millions of American Jews used their abilities and position to overcome isolationist and pro-Nazi movements in USA such as German immigrant’s Bund. It was a high stakes ideological struggle outcome of which was not known at the time. If Jews lost this fight it is quite possible that Germany would achieve victory in Europe with USA standing by or even helping Nazis. This would inevitably lead to much more difficult for USA war against united national-socialist Europe that would have to be conducted for decades to come.
2. European immigrants many of them Jewish contributed technological knowledge that culminated in creation of nuclear weapons. It was used against Japan, but there is no doubt that if Nazi lasted a few more months it would be used against them.
3. Millions of Soviet Jews used their communication skills, technological and managerial abilities to contribute to Soviet victory. It was not a small deal because Jews while small minority provided non trivial numbers of top engineers, scientists, and managers way out of their proportion in population.
4. Being traditionally more or less community interconnected across border in Europe and well familiar with multiple cultures and languages Jews provided significant services in intelligence.
5. Finally at least hundreds of thousands Jews directly participated in fight as soldiers and officers in all armies of anti-Nazi coalition, partisans, and saboteurs of German war effort.
In short even without state or any other organization the sum total of individual efforts was qualitatively higher then just their numbers. This qualitative difference could be demonstrated by counterfactual thought that if Germany remained culturally and politically the same way it was during WWI and all these Jewish scientists who participated in creation of American nuclear bomb would remain Germans, Italians, and citizens of other European states, the outcome of war could be quite different then the one which actually occurred.