Explain how Germany's invasion of the Soviet Union and Japan's attack on Pearl Harbor turned a European conflict into a fully global war.
On June 22, 1941, Germany launched Operation Barbarossa, breaking its own non-aggression pact to invade the Soviet Union with the largest invasion force in history. German forces made staggering initial advances, but -- in an almost exact echo of Napoleon's catastrophic 1812 invasion of Russia from week 3 -- failed to capture Moscow before winter set in, leaving Germany trapped in the two-front war that history's military strategists have long warned against. It is a striking pattern: two different conquerors, 129 years apart, made nearly the identical mistake of invading Russia without securing a quick victory before winter.
Just months later, on December 7, 1941, Japan launched a surprise attack on the United States Pacific Fleet at Pearl Harbor, Hawaii -- a decision shaped partly by an American oil embargo imposed in response to Japan's ongoing aggression in China and Indochina. The United States declared war on Japan the next day, and on December 11, Germany and Italy, honoring their alliance with Japan, declared war on the United States in turn. Within a single week, a conflict that had been centered on Europe and Asia separately became a single, fully global war, uniting an unlikely "Grand Alliance" of the capitalist United States and Britain with the communist Soviet Union against the Axis powers of Germany, Italy, and Japan.
Mastery looks like: They can explain Operation Barbarossa's failure as a direct historical echo of Napoleon's 1812 invasion, and trace the exact chain of events that turned a two-theater war into one fully global conflict by December 1941.
Common stumbles: Treating Barbarossa and Pearl Harbor as unrelated events rather than recognizing how together, within months of each other, they made World War II a single global war, or missing the deliberate parallel to Napoleon's invasion of Russia.