"and admit their horrific acts" - I don't think any person from the UK/US has engaged in any of this (both educational systems teach about the wrongs of the Empire and American expansionism at the cost of natives AFAIK), but you're prescribing guilt, it's vindictive madness. Does a child born in the UK from African parents inherit this sin?

A person may be free from guilt, but a nation is not. I can, with absolute certainty, tell you that the educational system of the Uk does not go into details on the horrific acts of their empire, they do not get into details of how they pitted communities against each other and orchestrated coups all around the world that resulted in 'interventions', all premeditated, they do not go into details on the torturing they committed.