IV:13 Top-heavy empires lacking a middle class foundation to support it will ultimately collapse.
Without a middle class, there would only be the wealthy, the poor, and the law of gravity. The wealthy would essentially control everything from above, including the government, without any direct connection to the needs of the population on the ground level, creating the perfect storm for corruption, oppression, and eventual revolution.
When an oppressed population unites, it becomes a powerful force that will easily knock out the stilts propping up the elite, sending them into freefall through the empty space where the foundation would normally be. The former elite will hit the ground hard and find themselves at the mercy of the oppressed population, a situation that, given humankind's penchant for violence and vengeance, will not end well for the fallen.
On contemporary Earth, one such top-heavy empire fast approaching collapse is the United States of America.
The American empire has become so top-heavy that the uppermost 1% of the wealthy own more than the other 99% of the wealth combined. Such disparity is not sustainable. American humans, prideful of their revolutionary heritage, will in all likelihood revolt sooner rather than later if the middle class becomes endangered. The American empire was headed down a similar road during the 1930s when it was weakened to the point of vulnerability by the Great Depression and perhaps would have collapsed if not for the attack of Pearl Harbor by the Japanese. The emergence of a common external enemy united the American humans into an unprecedented burst of production and technological advances that laid the groundwork for middle class prosperity after World War II. With the strength of unity, the American humans built one of the most powerful empires in the history of humankind, one that was built to last on the foundation of a strong middle class.
In more recent times, cracks have appeared in this foundation. The middle class, damaged and embittered at attempts by upper class con artists to bilk it out of its savings through the sale of worthless financial products—a practice that nearly caused the global economy to collapse and commenced a severe worldwide recession—has shrunk, its collective wealth being consumed by an upper class that either fails to see or is apathetic to the dangers of hoarding too much of the overall wealth. A shrinking foundation is supporting a structure that is continually getting heavier. The increasing pressure from the added weight has caused the middle class to turn against one another and has rendered the government a dysfunctional house divided by self-interested politicians who address only the needs of its preferred constituents and are unwilling and/or unable to work out compromises that will benefit the entire population.
The American empire is deflating rapidly. Fortunately for the United States, there is still a large enough middle class foundation to support the weight above, and there is still time for the upper class to correct its destructive course, but the irrational behavior of American humans and their elected officials give no indication that a change of course is in the works. Continuing down this road will inevitably lead to demise.
When the American empire goes down, China will likely go down with it, as it will not be able to recover from the loss of its largest customer—a business relationship that has strengthened China's own middle class. The global economy will quickly collapse, sending humankind into a prolonged and severe economic depression exacerbated by the extreme overpopulation of the human species on Earth.
In ruin, however, there is opportunity, and a new empire will eventually emerge if humankind manages to survive. Hopefully, for the sake of humankind, history will be an appropriate lesson in building a new global society that will accommodate all and safeguard against any form of oppression that could doom it to becoming only the latest turn in the cycle.