I'm looking for specific and non obvious answers. Give me something visceral, rid the world of a figure or nation you hate. Preserve a culture you adore. It doesn't have to make sense either, you are basically god here.
What I mean is don't just say you'd get rid of imperialism or colonialism bc no shit
Personally I would make it so that the Americas are never discovered by the old world and every "would be" conquistador (especially cortez and pizarro) explodes.
If we're dreaming let's give all the Native Americans vaccines and more diverse immune system genes. Or maybe teach the Europeans germ theory and basic hygiene before 1492.
The British were giving out smallpox blankets well before germ theory. I don't think a more precise understanding of the mechanism of contagious disease transmission would have helped.
Unfortunately they would probably just use that knowledge to better exterminate people. Idk if we are ready for the consequences of knowledgeable biological warfare in the 1500s
Preventing genocide by teaching British people to bathe
You're right, that's unrealistic. It makes more sense to travel back in time 600 years and vaccinate 100 million people.