The good earth has been abused too long and is now threatening to take vengeance on the human animal. In early times closeness to the sea helped the Phoenicians, Athenians, Romans, Portuguese, Spaniards, Dutch, English and Japanese to use it as a system of defense, avenue of communication and source of food. Today all nations may have to resort to the sea again for food to supplement the existing diminishing resources. Continental peoples like the Indians, Chinese and to some extent the Russians have turned away from the sea. Rivers may serve as boundaries or as highways.
Rivers can also be means of irrigation.
The Nile, Yangtze and Jordan are examples. The Syr Darya is doing the same for the Russians in the Tadjikistan and Uzbekistan desserts. Climates can be stimulating in the temperate zones and enervating in the tropics. Few people take long afternoon siestas in North America, Northern Europe or Russia. Good or bad soil, adequate or inadequate rainfall affect both the spirit and technology of a people.