SHORT ANSWER
What is the mass dispersion of a population from their homeland?

diaspora

Explanation:

is a scattered population whose origin lies in a separate geographic locale.

Historically, the word diaspora was used to refer to the involuntary mass dispersion of a population from its indigenous territories, in particular the dispersion of Jews

the speech revealed that eastern european countries were no threat to their neighbors, which led to the creation of the truman doctrine i think this might be correct.

can you put the answers so i can you