I highly recommend Winston Churchill’s second book, The River War. This was written in 1898, when he was 23 years old, and provides some insight into his values and attitudes. It also establishes some patterns that remained in evidence for the rest of his life.

He is forthright about describing British failures and misconduct, but is careful to attribute these to the failure of individuals to live up to British principles, rather than as consequences of imperialism itself. This was especially so when it came to management of the natives. For example, the book created a scandal by accusing General Kitchener of “permitting” his Egyptian and Sudanese troops to slaughter the Mahdist wounded after the Battle of Omdurman. It was just not the British thing to do.
Twenty years later, he condemned Colonel Dyer as a “terrorist” after the Amritsar Massacre but did not in any way see the episode as a consequence of colonial dominance.
This pattern repeats itself throughout his career, in Ireland, Kenya, Palestine, the bombing of Dresden, many more times in India and so on.