I'm not "white", but haven't "white" people been demonised (killed) in Zimbabwe and such? In the Western world in the modern day it seems to actually be encouraged to be racist towards people with European ancestry by groups such as BLM and the prevailing social trends. I visited New York last year and there were a group of women protesting against "white people" in general and saying they had problems with things being "white".

Why would this hinge upon whether or not white people have been "systematically discriminated against" in the past anyway? If you judge whether or not someone is being prejudiced based on the behaviour of people who are no longer alive then you are proposing a system of "punishing the son for the sins of the grandfather", and let me assure you - if you go back far enough no one will be blameless.

Arabs would often enslave white people, in fact the name for the ethnic group "Slavs" is related to the modern word for slaves, because of the frequency of this. Slavs are a European 'white' ethnic group.