Changing The Past (CH fanfiction)

Many wish to go back into the past and change something, but they get told that if they do, they'll change the course of history. They say that it's not important, that it won't bring big changes and that it won't concern other people.
But if you change something to your will,
If You go back in time and change it,
It can have big consequences.
Consequences you never thought of.
They always say if you're in the past you shouldn't change a single thing.

So better don't even wish for that
Because once your wish will be answered
You will definitely change your mind when you hear about the results but maybe then it
It'll be way too late

"I just wished I could go back in time and change history like in this books about alternative history"

What if such book was written by someone who wanted to destroy the world? What if countries went into the past? First they think that the decision is in their hands but is it really? Or is their alternate future already planned for them?