George F. Kennan: "... ada keseimbangan optimal, tergantung pada cara...

"... ada keseimbangan optimal, tergantung pada cara hidup manusia, antara kepadatan populasi manusia dan toleransi alam. Keseimbangan ini, dalam kasus Amerika Serikat, bagi saya tampaknya telah dilampaui ketika populasi Amerika mencapai, paling tinggi, dua ratus juta orang, dan mungkin jauh lebih sedikit."

--- George F. Kennan

Versi Bahasa Inggris

...there is an optimal balance, depending on the manner of man's life, between the density of human population and the tolerances of nature. This balance, in the case of the United States would seem to me to have been surpassed when the American population reached, at a very maximum, two hundred million people, and perhaps a good deal less.