The Rise and Fall of the Great Powers is historical nonfiction, so these "characters" are actually nations or other international powers. Further, it was published in 1987, meaning that some information—particularly regarding the then-ongoing Cold War and the Soviet Union, which dissolved in 1991—is now out of date.

The United States

In large part, The Rise and Fall of Great Powers can be read as examining historical patterns of growth and decline in order to generate suggestions for how the United States can handle its decline in international power. Kennedy discusses the initial independence of the United States from British colonial rule as an instance of British over-extension; he then traces the growth of the United States as an economic and industrial power first and later as a major military power, ascending in the twentieth century to being one of two super powers in the Cold War. This period was characterized by a massive focus on military expenditures and expansion which, Kennedy argues, set the United States on a course for decline. However, it was not as unsustainable as the path taken by the Soviet Union, which is why Kennedy predicted the United States' victory in the Cold War.

Great Britain

Kennedy points to the beginning of the twentieth century as the peak of British power due to its early industrialization and colonial empires, and he tracks its decline throughout the twentieth century, noting the damage caused by the prolonged war with Germany during World War II.

The Soviet Union (USSR)

Kennedy notes the late industrialization of the USSR compared to other countries, yet he discusses its ability to channel massive energy into its technological, military, and empirical projects. Kennedy frames this as fundamentally unsustainable, setting the USSR on the path to collapse. This proved accurate, as the USSR officially dissolved in 1991, four years after the publication of Kennedy's book.

China

Kennedy notes the past dominance of Chinese empires damaged by the Opium Wars and predicts China's return to being a great power due to its economic trajectory.

France

France appears as a European power that, while able to establish a large colonial empire, was unable to keep up with Britain due to inferior industry.

Japan

Kennedy notes Japan's adaptation to an increasingly tech-based world economy and predicts Japan growing once again in world political significance.

Spain

Spain appears largely as an example of a great power that adapted so poorly to its decline that it is relatively insignificant on the world stage.

The European Economic Community (EEC) and European Union (EU)

The EEC, which has since been folded into the EU, appears as a coalition of many declined European powers. Kennedy is optimistic about its potential to function as a great power.