The children of men are being chastised for their refusal of Baha'u'llah

Shoghi Effendi in his letter addressed to the North American Bahá'ís titled "The Anger of God and His Correction" states that the World Wars are God's "direct interposition" being "the rod of both the anger of God and of His correction. The fierceness of its devastating power chastens the children of men for their refusal to acclaim the century-old Message of their promised, their Heaven-sent Redeemer."

http://bahai-library.com/shoghieffendi_this_decisive_hour#s82