1) Developed and developing nations face challenges from migrations, ethnic/religious conflicts, and new technologies. Migrations often cause displacement conflicts and guest workers migrate to cities. Ethnic/religious conflicts have shaped regions like the Middle East.
2) New technologies are unequally accessed between nations and have made societies more instantaneous through communication, leading to issues like genetic engineering and bioethics.
3) Countries vary in economic development, populations, and social conditions, impacting environments through pollution, urbanization, and climate change, posing social challenges like poverty and health issues.