In May, 1943, British, Canadian, and American captured officers were brought by the Germans to view the Katyn site. Although convinced that the Soviets were responsible, they made no statements after the war for fear of alienating their victorious ally, the Soviets. The Americans and British knew about Soviet mass murders during the war, causing the Soviets to justify their actions by alleging that the Germans had murdered many millions of unarmed prisoners of war.