The great classical cultures of Eurasia created separate identities but each of these cultures also contained important elements that other peoples adopted. In the classical and post-classical periods (600 BCE to 1450 CE), the peoples and cultures of this vast area had consistent and enduring interactions. What were three main causes or sources of this new integration of Eurasia

World war I is  initiated to be the  catalyst for the political and social change.

Explanation:

There were many social and political changes which were initiated in the first world war. Some of the social changes were the upheaval of fashion, people especially women started ton give up old and conventional way of dressing and they started to socialise. Urbanization also was initiated . Many started to migrated to cities for livelihood. women' rights were given importance.

Women staged protests and claimed equal rights on part with men as a citizen of the nation, they also asked enfranchisement rights. Civil rights started to begin which highlighted that all must be treated equally and overcome the racialist bias.

There were also major political changes. Many started to appreciate the success of  Democracy after the declaration of independence in America. Monarchy form of government were overthrown and people realized that they were the key factor ij the society.