Ww1 could have been prevented if it wasnt for an assasin who killed the Hungarian archduke and the huns to invade Serbia. Hope this helps some facts could be wrong
No
handwashing
No
WW2 prevented the total conquer of the Nazis over the world.
World War I
Neutrality laws
Neutrality laws
Neutrality laws
It prevented Europe from socially or economically recovering from the war
The Neutrality Act
It couldn't have, according to Dukish.
World War II prevented them from happening