The peak racist theory (rather racist practice) reached in Nazi Germany, when they tried to turn the whole world into the scene of fight between Aryan and Semitic races.
The Aryans were represented as superior race that is the only one that has such virtues as love of freedom and honor and spirituality worship.
So xenophobia is a state characterized by obsessive fear towards foreigners or anything unknown and foreign.
Namely it is one of the mental disorders of a person.
Over time the world became much safer, however the initial fear of everything foreign and strange rooted deeply in the subconscious of many people.
Xenophobia has many faces, many ways of expressing, such as racism, anti-Semitism, prejudice to other nationalities, islamophobia and other kinds of religious intolerance, discrimination against refugees, migrants and so on.
Important role in the elimination of apartheid was played by the activist Nelson Mandela, who was awarded the Nobel Peace Prize.
During the apartheid times he had to spend 27 years in a jail, and in 1994 he became the President of South Africa.
The Jews were represented as the embodiment of absolute evil that had to be destroyed.
As a result of such a police 7 million Jews were killed.