Why did West Africa's largest cities arise near or on the coast?

Why did un coalition troops battle iraqi forces in 1991? iraq had invaded saudi arabia, along with its other border nations.iraq had invaded kuwait, which was a major source of the world's oil.the united nations wanted to remove saddam hussein from power.the united nations wanted to prevent the trade of illegal drugs.

•the impact of enlightenment ideals on the development of economic, political, and religious structures in the western world

Why might the greeck city states have an advantage over the persians