The question is a counterfactual (hypothesis which depends on events which did not happen), and professional historians tend to avoid engaging with them because, by their very nature, you cannot cite sources or figures when discussing them-everything is speculation. The foundation of historical study is the ability to cite and discuss evidence, and 'what-if' scenarios preclude that. A better place to try this question would be /r/HistoricalWhatIf-in fact, I would hazard a guess that it's one of their most asked questions, and you can probably find a discussion of it in their wiki or FAQ.