No he does NOT mean that. There is something called geographic determinsm. That is your geography has strong effect on the evolution of people. It is no absolute as other variables apply but is is still potent. most of Afghanistan is natural extention of the Indus region. So is small part of India [Punjab mainly] but ony about 3% of Indians live in the Indus region. Whereas a good chunk of Afghan population including their capital Kabul falls in indus region. You may not like this but i can assure you the future of K-Pk is deeply intertwined with the Kabul region of Afghanistan through trade and people 2 people contact. Because as I mentioned whereas the two Punjabs are divided by religion the two Afganias are united by ethncity and religion.