Jacklin said:
In any case, numbers matter
Hitler was piss scared of Stalin, he found the west to be a pawn, compared to a massive hulking Soviet reign. When D-Day occured, the tiny 250,000 troops (mostly not American) were insignificant compared to what was happening in the east.
Just because it was the largest Amphibious assault ever, does not mean it was the most significant.
The Eastern Front was the largest front ever, the most total troops mobilized ever, the heaviest losses ever.
You cannot beat the beastly size of the Eastern front, plus D-Day being the most important in WW2 is insubstancial, look what everybody else is saying.
Sheer numbers alone don't indicate turning points.
Whist the Russian campaign may have been a major event, and perhaps a major turning point, D-Day at least allowed the allies a foothold in "Fortress Europe" and safe ports through which to invade and liberate Europe. D-Day might not have been possible if Hitler hadn't opened up a second front and started loosing through bad tactical decisions (not striking Moscow, going on through the Winter instead of falling back and digging in etc).
None of this (D-day) would have been possible without Britain being a free, largely-unscathed country (morale and training-wise we were lagging behind, but we were producing equipment quickly and still had a lot of infrastructure standing); giving the allies somewhere to launch the assualt, and bombing campaigns, from.
America wouldn't even have been involved, meaning Britain, though it could carry out D-day alone (or rather, with colonial support such as Canadians, Anzacs and Indians) it would have been a last-ditch effort (due to a lack of food and oil supplies, which came from America), without Pearl Harbour dragging them into the war. This also cut off American supply to the Germans (yes, they were selling the Germans stuff too, it's what happens with isolationist policies).
Japan wouldn't have been forced to attack Pearl Harbour if it wasn't for signing an alliance with Hitler, and for the humanitarian crimes in China (since America only cut off the oil supply, and the whole attack was because Japan was short of oil so wanted to neutralise America's Pacific Fleet and go and get oil from other countries').
America might still have been defeated by Japan had they not had outstanding luck eliminating Japan's carriers at the Battle of Midway (and Japan's bad luck of not eliminating them in Pearl Harbour).
Lord, WW2 may not have even happened if Clemenceau wasn't so eager to punish Germany for WW1. Woodrow WIlson counselled against the harsh reparations and military limitations, and Lloyd George (though he wanted small reparations to fix what was done to France and British lives) was also against harsh measures.
The smaller campaigns through Africa and Italy meant that Hitler was kept on his toes, and the defeats of his armies (especially in Africa) prevented a consolidation of resoures, new recruits and re-deployment of forces in foreign theatres.
Anyway, I'm sure I've gone off making a point...oh yes, sheer numbers don't matter. Essentially, I don't think any *battle* was the turning point of WW2.
The turning points were, in my opinion:
1) Capture of the Enigma Machine
2) Germany turning to "super weapons" (such as the Konnig Tiger) that were rolled out too soon and had too many problems/maintainance and supply issues/too little too late to compete with Allied production (both American/British production of Shermans/Churchills and Russian T-34s).
3) Severe bad luck on the part of the Axis forces (particularly the severity of the Russian winter, the fact Carriers weren't in port in Pearl Harbour, that Hitler stopped bombing the Airfields to try to break morale - when a few more days of bombardment would have crippled the RAF, that the American squadrons sank the major Japanese carriers at Midway - finding them by luck, that Monty was able to turn defeats into victories in Africa and so on)
Had Germany's codes not been broken then they would have been more successful in sinking American-British and British-Russian supply convoys; if they had stuck to "normal" tanks and/or begun research into thier jet fighters sooner they may have broken the allied forces, had Hitler not forces his generals' hands creating bad decisions and had they had a little more luck then things might be totally, totally different. None of these are a single battle, but rather the culmination of all coming together (ie, had D-Day not been underway, or Britain fallen and America out the war, then I'm sure the defeats in Russia wouldn't have been so disasterous).
I've already voted "Other" for the mighty Enigma machine. Intelligence is what makes-or-breaks wars (and sheer good luck).