The gradual decline of a society is often a self-induced process of trying to meet ever-expanding appetites, rather than a physical inability to produce past levels of food and fuel, or to maintain adequate defense.

Often, the pretexts for starting a war are not real shortages of land, food or fuel, but rather perceptions - like fear, honor and perceived self-interest.

History has shown that a government's redistribution of shrinking wealth, in preference to a private sector's creation of new sources of it, can prove more destructive than even the most deadly enemy.

In history, one gathers clues like a detective, tries to present an honest account of what most likely happened, and writes a narrative according to what we know and, where we aren't absolutely sure, what might be most likely to have happened, within the generally accepted rules of evidence and sources.