From Hagrid and a book i read they stated,"In old times, tariffs was used heavily on countries that dominating nations have conquered as a form of punishment towards the citizens in order to effectively command/control them. It's simply like how authorities punish criminals."
stated so this answer is right (plus I read something about this0
Over the last 20-25 years there has been many terist attacks around the around the world like 9/11 the bombing of Pearl Harbor and many more but now we have not seen or heard of any terist but they did catch some so in my opinion it reduced.
