1 The problem with all these cycle-of-history analyses is that most of human history happened pretty close to a bare minimum of population, wealth, range, and technology, and we're so far off the map that you couldn't perceive any ellipsoid stretched to include us as a "cycle".

Just like WWII was something the world had never seen before, atomic weapons are something the world had never seen before. 7 billion people dependent on the frictionless functioning of an overheated global technological system to eat has never happened before. Global communications have never happened before: The interaction of our brains with computer-mediated media, and the sheer hypertrophy of micromanagement, oversight and bureaucracy that computers enable have never happened to this extent before.

Pretty much every civilization up through 20th century continental Europe could die and people would pick up the pieces and restore some sort of order with little lost. This civiliztion is more than who parks what tolls on which roads: The machinery is necessary to sustain our population: If this civilization blows up, the die off could be unprecedented.

2 /One/ problem with all the cycle/trend of history analysis.

There's a more general category of error.

All of our observations of history are past. 

This isn't a problem when we form theories about widgets, because it is usually safe to assume that a widget is not able to choose to change its behavior based on opinions about the observer, or what is going on.  So a widget measured in the future doesn't know the date, and might have the same measured response to the test that a widget measured in the past would have.

Okay, some joker may start talking about smartphones, but the transistors are transistors, and cannot, for example, let out all the magic smoke and then decide to start working again. 

So, a lot of time you look at humans, and they aren't motivated to screw around with you, so they aren't putting on much of a show for you.  And you can take those observations, and formulate rules or a model that describes them, and it may even be useful predicatively.  But mess with them, give them incentive to screw with you, or force them to dance for you, and you may then find yourself surprised.

You can look at people, maybe figure out their magical thinking, and then maybe use that magical thinking to manipulate people.

Manipulation is a somewhat common human behavior. 

When a lot of people are doing it, it becomes obvious to some of those they are manipulating. 

The manipulated people can in principle choose to avoid that magical thinking. 

One remedy to that countermeasure is using force to scare people away from quitting the magical thinking. 

Once a regime is deeply invested in using this to prop itself up, it becomes fragile.  If it loses the force, it loses the magical thinking, and disappears. 

This theory could explain the late bronze age collapse.  Some group of failures cost that brand of kings their reputation for mojo, so people decided they no longer got anything for tribute/taxes.

Also, around 33 years ago in 1988. 

For good parts of the historical record, the populations involved were not necessarily scholarly enough for magical theories derived from the historical record to take hold of the public consciousness.  They had oral history, but that would ahve been 'my grand daddy said', and mostly not 'what this officially approved scholar said'.  So, you were not having a lot of manipulative jerks trying for general consumption to appeal to magical theories of historical forces.  China and some few other cases being more of an exception. 

Marxism is currently a popular family of religions/heresies, and Marxism is definitely such a superstitious belief.  We thus now have a lot of people trying to use this magical theory to manipulate folks. 

We should expect a greater degree of such scams than were widespread pre-Marx, more such scammers, and much more frequent backlash as a result. 

You should be careful how seriously you take any cycle of history/trend of history theory.  The more people in power take it seriously, the more likely it is that they are gaming it for power.  If they are gaming it for power, there is a risk they tick off enough people to prompt a behavior change that upends that theory.