After the Japanese attack on Pearl Harbor on 7 December 1941, followed by Nazi Germany's declaration of war on the United States four days later, and the United States' declaration of war on Germany in response, Hitler authorized a mission to sabotage the American war effort and attack civilian targets to demoralize the American civilian population inside the United States. The mission was headed by Admiral Wilhelm Canaris, chief of the German "Abwehr". Canaris recalled that during World War I, he organized the sabotage of French installations in Morocco, and that other German agents entered the United States to plant bombs in New York arms factories, including the destruction of munitions supplies at Black Tom Island, in 1916. He hoped that Operation Pastorius would have the same kind of success they had in 1916.