The Soviet Union and its empire disappeared in large part because its smokestack economy could no longer keep up with the technological progress of the world's major economic powers.

A state's potential power is based on the size of its population and the level of its wealth.

The most dangerous states in the international system are continental powers with large armies.

Decapitation is a fanciful strategy.

Important benefits often accrue to states that behave in an unexpected way.

When World War II started on September 1, 1939, the German army contained 3.74 million soldiers and 103 divisions.

In the 1930s, Adolf Hitler believed that his great-power rivals would be easy to exploit and isolate because each had little interest in fighting Germany and instead was determined to get someone else to assume the burden. He guessed right.