6 million Jews were killed by the Nazis, many by starvation, but many through a chillingly planned effort of extermination in death camps. These death camps can be distinguished from concentration camps or labor camps in that their primary purpose was extermination of Jews, Roma people, communists, homosexuals, disabled people, and others that the Nazis deemed unfit. Some historians believe that the Nazis opened the death camps because the Jews weren't dying as fast as the Hunger Plan had intended. This was a sickening plan, but it made a kind of demented sense. Rather than becoming more involved in global trade as the British had, the Germans would feed themselves by taking land and killing the people who'd previously lived there. Similarly, Japan at the beginning of the war was suffering from an acute fear of food shortage because its agricultural sector was having trouble keeping up with population growth. And the Japanese, too, sought to expand their agricultural holdings by, for instance, resettling farmers in Korea.