How did Cyrus the Great and Darius I each rule diverse groups of people peacefully?

The ethno cultural diversity of the various nations beneath the decree of Persia, its massive geographic extent, and the relentless scuffle for authority by regional contenders, the establishment of a skilled army was compulsory for the preservation of the peace, and also to impose the power of the king in circumstances of revolution and foreign menace.

Explanation:

world war i had a devastating effect on german-americans and their cultural heritage. up until that point   german-americans, as a group, had been spared much of the discrimination, abuse, rejection, collective mistrust experienced by so many different racial and ethnic groups in the history of the united states. indeed, over the years, they had been viewed as a well integrated and esteemed part of american society. all of this change with the outbreak of war.  

your answer is "graduates" hope this