What were some similarities between the European and Pacific theaters during WWII?

In the European and the Pacific theaters, the United States faced a well-trained, well-disciplined, and initially well-equipped enemy. Both the Japanese and to a somewhat lesser extent the Germans (many of whom, by the end of the war, were conscripts) were fanatically devoted to their cause and reluctant to surrender. This was especially true of the Japanese, who had a strong cultural bias against surrender, which made them both difficult to defeat and especially brutal toward American captives. Strategic air power was important in both theaters, as the Allies reduced almost every major city in Japan and Germany to rubble before finally forcing surrender. Indeed, the Japanese were forced to surrender by the devastating might of American air power without the necessity of a ground invasion. Obviously the Pacific war was more of a naval war, but both theaters witnessed massive amphibious assaults on such beachheads as Anzio, Normandy, Saipan, and Iwo Jima. Some of the city-to-city fighting that characterized the conquest of France and Belgium was also witnessed in the Philippines. Obviously, there were many differences between these two conflicts—World War II for the United States was in reality two different wars—but in terms of human loss and the amount of military power that had to be brought to bear in order to achieve victory, they had much in common.