"food was rationed to two pieces of bread a day. desperate leningraders ate almost anything. for example, they boiled wallpaper scraped off walls because its paste was said to contain potato flour." which nation was the aggressor in the action described here? the soviet union japan germany italy

Germany was the aggressor nation.  The event described was the siege of Leningrad, part of Germany's World War II aggression against the Soviet Union.  The siege lasted from September 1941 to January 1944, a total of 872 days.  More than 1,000,000 Soviet civilians died during the siege.  (German forces had finally weakened by then.)