North American citizens may have forgotten about actions taken by their own government against indigenous peoples in 'modern' times. (Which preceded those of Germany, Japan and China.)

https://en.wikipedia.org/wiki/Trail_of_Tears

https://en.wikipedia.org/wiki/American_Indian_Wars

https://en.wikipedia.org/wiki/California_Indian_Wars

https://en.wikipedia.org/wiki/American_Indian_boarding_schoo...

https://en.wikipedia.org/wiki/Canadian_Indian_residential_sc...