What were characteristics that pulled the greek city states together?

The characteristics that pulled the Greek city states together were a common language, and whorship to the same gods.

Explanation:

Ancient Greece is the common name for the territories of city-states that were inhabited mainly by Greek-speaking tribes: Aeolians, Achaeans, Ionians and Dorians.  Ancient Greece is considered the cradle of Western civilization, and Greek culture, art, mythology, philosophy, science were transmitted to Europe through the Romans and exerted a great influence on its inhabitants at various times in history.

In addition to language and culture, these tribes shared a common religion: Greeks practiced an anthropomorphic polytheistic cult, in which the gods could engage in fantastic adventures, with the participation of heroes (Hercules, Theseus, Perseus, Oedipus) who were considered divine. There were no dogmas and the gods had both virtues and defects, which resembled mortals in terms of personality.

climate change is the big reason to the decline of the indus valley which also caused floods. so i dont know what answer would best fit the description thats just what i found online! have an awesome