The Cold War was a period of tension between Communist countries and Western countries taking place after World War II. Although there was no physical fighting, the constant race to develop the best weapons and armies pushed each country to new scientific discoveries. In Western countries, Communists in the Soviet Union and China became labeled as "enemies." This dehumanization surrounded many Western countries. Because Ishiguro lived through the Cold War, he would have understood firsthand what that dehumanization would have meant. There is traces of this type of treatment in Never Let Me Go. Since they were little, the characters have the idea that they have this "otherness " about them. The division between them and the rest of the world only increases, especially as they figure out that people don't believe that clones have a soul. This dehumanization serves as an underlying presence throughout the book, and was verly likely influenced by Ishiguro's personal experiences. 

Cold War: Summary, Combatants, Start & End | HISTORY

Cold War | Summary, Causes, History, Years, Timeline, & Facts | Britannica

"Cold War alliances mid-1975" by Vorziblix is marked with CC0 1.0.