Why was marriage between two different races a crime?

Apartheid  

Apartheid was a system of institutionalised racial segregation that existed in South Africa and South West Africa from 1948 until the early 1990s. one thing about this law was that it forbade people of the opposite sex to mate and marry each other.

now this is no longer a problem, but that doesnt mean that it was okey, the people that praised and agreed with this form of racism is just as bad as the people who inforced it.

hope this helps ;)

ask google there you might be able to find an answer for the question you're trying to ask

they were all fought in the middle east during ww1