Operation Pastorius: The History of the Nazi Intelligence Operation to Commit Sabotage in the United States during World War II

Four days after the attack on Pearl Harbor, Hitler declared war on America, almost casually and without seeming to consider the consequences. There was no diplomatic necessity for him to have done this and no obvious strategic reason. Germany's military successes were so complete at that point that Hitler seemed to believe declaring war on one more country was a trifling matter.

In some ways, he was right, because in December 1941, the US Army was tiny and poorly equipped. In September 19...