This is the first in a projected series of volumes of essays selected from World Politics, a journal of international relations sponsored by the Center of International Studies at Princeton University. The articles touch on several related subjects: the nature of national power and power balances and their perception; strategic studies; strategic surprise; the utility of military force; and national security decision making. Originally published in 1983. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.