What Is Collapse?
Tension. It's strange how humans can process the feeling of it regarding the sentiment of an entire country. A heightened level of paranoia that at any given moment the strings holding everything together will finally be over-tightened to the point of snapping, bringing the entire system crashing down. But what does a collapsed society really look like? Many of us probably have mental images from movies and books but who's to say if that resembles reality. Fortunately, many civilizations and societies have collapsed throughout history and we can use their shortcomings to better understand our own.
"A generation which ignores history has no past and no future." -Robert Heinlein
Collapse Defined
The basic Wikipedia definition: "Societal collapse is the fall of a complex human society characterized by the loss of cultural identity and of socioeconomic complexity, the downfall of government, and the rise of violence."
Regarding state collapse: "State collapse, breakdown, or downfall, is the complete failure of a mode of government within a sovereign state."
However, historians who study civilizations and their collapses have their own definitions:

Historian and author, Jared Diamond, defines collapse as "a drastic decrease in human population size and/or political/economic/social complexity, over a considerable area, for an extended time."
Historian and anthropologist, Joseph Tainter, defines it as such: "...' collapse' is a "broad term," but in the sense of societal collapse, it is "a political process." He further narrows societal collapse as a rapid process (within "few decades") of "substantial loss of sociopolitical structure"
Joseph Tainter's definition saying 'collapse' is a broad term is true, as collapse can range from large-scale empires (societal collapse) to modern-day countries (state collapse) to standalone system failures (economic collapse). Collapsology, or the study of
societal collapse is a complex topic and is often comprised of many different subjects such as anthropology, ecology, economics, sociology, political science, and history.
Brief Examples
There have been many societal downfalls in history, to name a few and their respective categories:
1. The Western Roman Empire aka The Fall of Rome (Societal collapse)
2. Yugoslavia (State collapse)
3. 2008 U.S. Economic Crisis (Economic collapse)
4. The Rapa Nui of Easter Island (Tribal collapse)

What exactly caused these to fail? How can a massive empire crumble?
There's a number of factors that can play a role in a collapse, some compounding each other.
Environmental or climate change
Resource depletion
Invasion
Disease
Decay of social cohesion
Class inequality
Overall decline of cognitive abilities
Loss of creativity
These are just a handful of factors that can contribute to collapse. The numerous factors, subjects, and variables can be analyzed as what is known as a complex system.
The causes are only half the battle. What are the effects on civilizations?
Social upheaval, coup d'états, civil war can all lead up to the collapse. Afterward, civilizations can revert or simplify their ways of living, they can be absorbed by other nations, they can evacuate or become completely extinct. Many of us envision a post-apocalyptic wasteland, with abandoned buildings and vehicles littering the roads but who's to say that Hollywood's depiction is realistic?
The Collapse Series
This article is the beginning of a journey to uncover what collapse really looks like: content about the theories, models, expert predictions, and case studies of previously fallen societies. We can use these tools to better understand our modern world and make our own predictions of where things are heading.
Creating this content is going to be a marathon. It requires researching, reading, and writing for each topic discussed, all time-consuming tasks. With the self-set schedule of publishing weekly articles, I will be devoted to creating this series. That being said, I would love to recruit other writers who would like to write about collapse, current events, concerning news...whatever you enjoy writing about that fits the theme! Contact me at doomkaiser@doomtheory.com and we can chat about it.