World War II: 12 things to know

Tensions rise in Europe and the Pacific

War begins as Hitler invades Poland

Axis powers line up for war

Japan bombs Pearl Harbor

Allied powers prepare to fight back

Soldiers ship out overseas

Life changes almost overnight for US citizens

Battle of Midway rages in the Pacific

Battle of Stalingrad ends in German defeat

D-Day leads to victory in Europe

US bombing causes Japan to surrender

High price of war takes its toll

Key dates.