Himmler gave the speeches at a time when German military setbacks were mounting and the Nazi political and military leadership were privately expressing alarm. At the Casablanca Conference in January, 1943, the Allies had decided that the only acceptable outcome of the war was Germany's unconditional surrender. The Soviet victory in the Battle of Stalingrad on 2 February 1943 was a turning point in the war. US President Franklin D. Roosevelt announced the prosecution of those mainly responsible for war and genocide on 12 February, which the US Congress agreed to on 18 March. US and British troops landed on Sicily on 7 July 1943 and successfully invaded the Italian mainland on the 3 September, and after the Italian armistice on 8 September, gradually advanced northward. On 1 October, Naples was freed from German occupation.