Before I get started, I'd just like to say this: If I am wrong or inaccurate in some aspects and make myself look like a fool, I am inexperienced and have taken no real course on modern history or history at all for that matter, and am only 15, where as most of you are probably atleast in their late-teens or 20's (atleast). And I don't mean to repate, but it disrupts my line of thought to cut out chunks of my arguement...now, that said...
I don't think you can peg any one reason onto why the Allies won WWII. I don't think you can peg any one reason onto why a particular force wins any large scale conflict, but rather that it is a combination of factors. The Allies won World War II for many reasons. I heard someone mention that America made itself nearly entirely self-sufficient. I would hope so, from what I see the USA's landmass appears to be atleast equal to the landmass of all Europe combined, and I'm quite sure all of europe as one could be self-sufficient - they were before imperialism. One of the huge things that allowed the Allies to win, in my oppinion, is that they managed to hold the UK. Had it fallen, the last spot of major resistance in Europe and the last base for the allies would have been gone. Africa there still was to fight, but with all of the Europe under Hitler's hand he would have would have been free to devote those units formerly dedicated to conquering Europe to Africa and the Eastern front. I may be wrong in this, but it is my oppinion that had the Germans continued there original campaign of bombing the production and military sites and facilities of the British, they would have destroyed all effective resistance of the RAF and had superiority of the air allowing superiority on the Channel and an invasion of the UK by a ground force. Which is in my mind also another huge matter, for it is my oppinion that had the Germans managed to make it to Britain, every man, woman and child capable of holding a weapon would have stepped up to avenge their fallen relatives and comrades, defend their nation, their pride and their way of life. I think that the British knew what was at stake, and would have faught nearly to the last until they were submissable. This would have taken quite some time, and a large amount of manpower. I have heard of the Scots going to war in the middle ages and having 90% of their male population killed off, and believe a similiar situation would have evolved in the UK, but quite possibly with overall population instead. For sure in my mind they would have after the German bombing campaign shifted to the idea of demoralization through mass civilian casualties, and quite likely even if they had stayed true to the original goal of the military minds instead of having Hitler interfere. Which is one of my other reasons that the Allies won, was that Hitler became impatient with the campaign on the western front, and got pissed off and decided he would just smash the hell out of them for their stubborness (in my mind), and instead of demoralizing them gave them more of their famous British fighting spirit, despite that they were months (possibly weeks?) away from breaking the RAF. The allies also won because the German forces, whose tactics and entire war was based on blitzkreig tactics (which seem in my mind to be based on causing an initial spree of havoc from which the enemy command never manages to recover...hopefully because you've broken through the line far enough to take them out.) became stalled and mired in the east in a war of attrition which the military people knew they would lose against a larger enemy, and a larger enemy was both the US and the Russians. It may have been part of the agreement with Japan, but the US only enterred the war full-fledged (if i recall correct) because Hitler declared war on them. Sure, the UK had North America's backing before, but where would all those shipments of support go if the last allied port over there fell? If the UK fell the only way to come at the Germans would either be from the East, through Russia and the Middle-Eastern country-states (whatever they were/are called...I'm not sure about it), or to send a mass invasion fleet across the Atlantic, which isn't something I would want to do when I've got Nazi bombers and fighters coming in at me on runs all the way across the atlantic. Now, I suppose I do aswell then also disagree with the idea of the UK/Western allies being sideline players, because if the UK had fallen those extra forces - maybe not fresh, but fresh from a major victory and a few days of rest en route to the new front - may have turned the balance of the East to their favour. The appearance of seemingly new and fresh troops at the proper moment can absolutely devastate moral, and that effect would also have to be factored in to it. I know that life under the Germans, to me atleast, would have sucked, but I do not know how much worse it would have seemed to those Russian conscripts than life in Russia under Stalin. And once again the sheer numbers deal comes up again. It may have taken 10 russian tanks to take out a tiger, but for each tiger there if there are (which there probably was) 100 enemy tanks, the massive, low-quality force will win. So, to sum it up, I suppose the reasons the Allies won, in my oppinion are:
1. Hitler thought he could do everything better himself
2. The UK held (due to 1)
3. The Russians held (also partially due to 1)
4. The Americans finally joined the war full-on (not due to one, but closely related to.)
5. The Allied forces completely outnumbered the superior quality but massively inferior numerically Axis forces and equipment.
These are not in any particular order, and their are other massively influencing reasons that did not get mentioned due to length and that it is nearly 0300 here and i need to get to bed (so say my parents...).
Someone mentioned superior tech on the Allies side I think, and that is off. The Germans had better tanks (the King Tiger anyone?), better guns (the MG42? any takers?), better fighters (the jet engine for starts), and they had missiles (the V1? and definately V2)
That is my rant and thanks for your time. All feedback is welcome and appreciated. Please pick to shreds any fact that is wrong here and pit your oppinions against mine to the best of your will, but if they are that - say so!
Also as a last note, I apologize for the way this post has been all over the place. I only have a few weeks till school starts, and I gotta get my chaotic writing in somewhere....after that it's all mindmaps and structure essays and that junk.
Good Night.