The links between American slavery and trans-Atlantic slave trade to Christian supremacist thinking is well known as it the connection of the same supremacist thinking to colonialism.  What is not so well known is that there is a resurgance of white supremacist terrorism in Europe and these European groups are increasingly forming alliances with the heavily armed white supremacist militias in the US. The leaders of the Christian white supremacist groups especially those leading political parties in Europe are allowed easy access to the US where they come to raise funds and strengthen the trans-Atlantic ties. This fact is making the white supremacist threat worse by the month. These facts are documented by centers doing research on Christian white extremists such as the Anti Defamation League and Souther Poverty Law Center

https://www.adl.org/resources/reports/hate-beyond-borders-the-internationalization-of-white-supremacy

https://www.csis.org/analysis/rise-far-right-extremism-united-states

https://www.adl.org/resources/backgrounders/christian-identity

https://www.economist.com/international/2019/03/21/why-white-nationalist-terrorism-is-a-global-threat

https://www.citizen-times.com/story/opinion/2019/04/14/barbarians-and-white-supremacists-inside-gate-christianity-opinon/3440480002/

https://www.counterextremism.com/european-white-supremacy-groups

https://www.splcenter.org/fighting-hate/intelligence-report/2014/white-identity-worldwide

https://www.splcenter.org/fighting-hate/extremist-files/ideology/anti-muslim

http://www.islamophobiaeurope.com/wp-content/uploads/2018/07/EIR_2017.pdf

https://www.researchgate.net/publication/267397111_Shifting_borders_Islamophobia_as_common_ground_for_building_pan-European_right-wing_unity