In World War I Imperial Germany faced the daunting task of fighting Great Britain, France, and Russia (replaced in 1917 by the United States) at the same time. Mindful of the unfairness inherent in passing judgment in hindsight, we can usefully ask whether Germany might have won the war even against these odds had it not made too many serious mistakes. “What if?” history of this sort can help us understand better what actually happened, and it can provide precautionary lessons for the future. Here is a list of key German mistakes, omitting errors at the battlefield level, in this colossal human tragedy.