One reason that the city-states could of greece could not come together or unite into one nation is because:

One reason was because of the mountainous, and rugged geography .

the committees of correspondence were the american colonies’ means for maintaining communication lines in the years before the revolutionary war. in 1764, boston formed the earliest committee of correspondence to encourage opposition to britain’s stiffening of customs enforcement and prohibition of american paper money. the following year, new york formed a similar committee to keep the other colonies notified of its actions in resisting the stamp act. in 1773, the virginia house of burgesses proposed that each colonial legislature appoint a committee for intercolonial correspondence. the exchanges that followed built solidarity during the turbulent times and bring about the formation of the first continental congress in 1774.

france,russia and prussia had absolute monarchy and it meant:

when louis xiv inherited the throne, he was able to serve as his chief minister.louis xiv ruled as an absolute monarch.