Division emerged over the length of time taken by the Western Allies to establish a second front in Europe. Stalin and the Soviets used the potential employment of the second front as an 'acid test' for their relations with the Anglo-American powers. The Soviets were forced to use as much manpower as possible in the fight against the Germans, whereas the United States had the luxury of flexing industrial power, but with the "minimum possible expenditure of American lives." Roosevelt and Churchill opened ground fronts in North Africa in 1942 and in Italy in 1943, and launched a massive air attack on Germany, but Stalin kept wanting more.