Which “nation … will ultimately lead the whole world”?

No progress is possible except through the power of the Holy Spirit and the Cause of God. Each of the Manifestations of God appeared amongst a nation and in a country which outwardly had no means of salvation or progress. But no sooner had those nations come under the shelter of the Cause of God than they excelled all the civilized countries of the world. Today, whichever nation raises the standard of the oneness of humanity and comes under the shelter of this divine power will ultimately lead the whole world. (Words of ‘Abdu’l-Baha, Mahmud’s Diary, p. 78)