What would happen if you can go back in time and stop ww1 and ww2 i really want to know

If I could go back in time to stop WWI and WWII from happening, there are two possible ways things could go. One way is that more countries would be at peace with one another. The other way is that we would be more at war with one another. The reason why either of these could go is, because WWI and WWII taught us what disaster is really like and what we don't want to happen again. However, if it didn't happen, more countries might not want to go to war because they never experienced that pain and doesn't have a mean for vengeance.

Britain and its empire stood alone against hitler and mussolini. in june 1941, hitler broke the non-aggression agreement with stalin and germany invaded the soviet union. in december, japan attacked the us and britain. the main lines of world war ii had formed.