n. The belief that something, particularly a country or a political or economic system, is undergoing a significant and possibly irreversible decline.
Other Forms
The declinists, we might say, will always be with us. Wherever anyone believes in progress, someone, possibly the same one, believes in decline. Declinism emerges today from the triumphalism of the right: In our greatness, conservatives say, there is much to lose, and many who threaten us. So, too, does it emerge from the pessimism of the left: Power corrupts, and the corrupt will get their comeuppance. At present, both impulses—triumphalist and pessimistic, chest-beating and self-lacerating—are on the upsurge. So too, then, declinism.
—Laura Secor, “That sinking feeling,” The Boston Globe, September 14, 2003
Nearly every sentiment and idea that Franzen relays about the fallen preeminence of literature has been expressed before, and better. No one needs to be reminded for the umpteenth time that Dickens was a popular sensation and that the audiences that once clamored at the docks for news of Little Nell now queue at the multiplex or congregate in cyberspace. Like Broadway, the fabulous invalid, the serious novel has seemed poised to breathe its last ever since electricity entered the home. As a cultural analyst, Franzen is simply the latest to join the chorus line of declinism: Gore Vidal has been signing the novel's death certificate for a half-century.
—James Wolcott, “Advertisements for Himself,” The New Republic, December 02, 2002
1988 (earliest)
In 1988 the United States reached the zenith of its fifth wave of declinism since the 1950s. The roots of this phenomenon lie in the political economy literature of the early 1980s that analyzed the fading American economic hegemony and attempted to identify the consequences of its disappearance. …

Although predominantly of a liberal-leftist hue, declinist writings reflect varying political philosophies and make many different claims. In general, however, they offer three core propositions.

First, the United States is declining economically compared to other market economy countries, most notably Japan but also Europe and the newly industrializing countries. The declinists focus on economic performance and on scientific, technological and educations factors presumably related to economic performance.

Second, economic power is the central element of a nation's strength, and hence a decline in economic power eventually affects the other dimensions of national power.

Third, the relative economic decline of the United States is caused primarily by its spending too much for military purposes, which in turn is the result, in Kennedy's phrase, of "imperial overstretch," of attempting to maintain commitments abroad that the country can no longer afford.
—Samuel P. Huntington, “The U.S. — Decline or Renewal?,” Foreign Affairs, December 01, 1988
Declinism has been called the "apocalypse soon" school of international relations. The word was coined in 1988 by Samuel P. Huntington, but the noun declinist appears in the Oxford English Dictionary, where a citation from 1831 mentions the "doctrine of the decline of science" and labels one of its proponents as "the leader of the Declinists." The opposite is triumphalism, which originally (circa 1964) referred to excessive or blind pride in the achievements of one's religion or church, but now has a broader mandate in the language (for example, excessive or blind pride in the achievements of one's country).