Keep in mind here that America tried to stay neutral in WWII (at least as far as direct military intervention was concerned). It was the attack by the Japanese (who were the German's allies) that brought the United States into the war. When you start a fight with somebody, and they kick your ass...that is your fault. Not the fault of the person who gave you the beat down.
This is funny, because Germany actually declared war on us after we declared war on Japan, and we were completely un-prepared for war before pearl harbor, when everyone and their brother signed up for the Army to go fight the Japanese, then we out-produced 'em
Of course, I agree that is wasn't the fault of the German people, but of their leadership. But also keep in mind that the Nazi Party rose to power based on the people who elected them to power. They were a republic at the time the Nazi Party rose to prominence.
Although Hitler was very good at telling people what they wanted to hear, Germany got royally screwed over with the treaty of Versailles and had a messed up economy, Hitler told the people "We can be great again, I will fix the economy and Germany will once again become a great world power like it was" Hitler had an amazing amount of power over people and was very charismatic, and became the ('33 I think it was) Time magazine man of the year, he just used his abilities for bad.
Actually I read someplace that the American leaders were almost glad (although not for Pearl Harbor or the loss of life) to get a reason to take it to the Germans. Can't remember in what but I saw plans for Germans planned invasion of England.
My observations:
Had that happened it would have been a different war as we would have had no place to land planes or a safe zone for ships. no place to launch a D-day assault and the Russians would have been without any kind of support. The Germans were ten miles from Moscow at one point during the war. Had England fell the Russians might have drawn back and tried to hold up instead of advancing. They were the first troops into Berlin btw.
HM
The Germans actually did plan to invade england, this would have happened about '42 ish according to the alternate history book I have on the subject, although it is unlikely that that would have happened, Britain pretty much controlled the seas and the Germans had no landing craft, although they did make movies like
The Eagle has Landed about a German airborne drop into England to kill Churchill but I really doubt that England would have been invaded before Russia, they would have been pushed across the channel but after that it would have been put on hold, but on the Russian Front Germany came very close to winning, but what really stopped it, and here I go glorifying america again, but the invasion of Italy after Africa was taken opened up another front for the Germans to have to cover and mainly took Eastern Front people.
My 2 coppers on the subject (one of my favorites)
GM
EDIT with my main point for HM:
IF we had not entered the war, the British 8th army would have been driven out of Africa, then Russia would fall, then the Germans would develop landing craft, then America would have been the next target, maybe since we're over seas we would have been left alone, but assuming Hitler stayed in power and his economy didn't fall out from under him like some people predict it would have, then I think they were expansionist enough to come after us.