[MarkPNeyer]

The pressure analogy seems reasonable to me. It suggests that this goes both ways:

Two societies pushing against each other lead to pressure. This pressure results in military conflict. Whoever wins the military conflict can exert increased pressure.

The necessity of winning wars put pressure on the society to develop better ways of winning wars. These better ways put more pressure on external societies, etc.

China was the most wealthy, educated civilization in the world in the 1400's. They stagnated basically becuase there was little to no fighting.

Meanwhile Europe was busy finding newer more elaborate ways to slaughter each other, and to avoid being slaughtered.

[ComteDeLaFere]

-> They stagnated basically because there was little to no fighting.

A fair assessment, but now I realize that another way to say this is -

They stagnated because there was little to drive innovation.

Stated this way, it at least makes us consider that there might be an alternative to constant warfare as a driver of progress. Maybe recognition of this is some kind of societal turning point as well?

[pixl97]

War may drive innovation, but it may also have other purposes. Like resetting service and management economies that spend lots of effort keeping themselves running but not producing products. People think that the more efficient businesses always win are wrong. A bureaucratic sector can wedge itself into the legal system and enforce inefficiency.

[hx87]

Modern capitalism, combined with the expectation that things should improve over time (which wasn't very prevalent until recently) can be one hell of a driver.

[redwards510]

> alternative to constant warfare

How about the existential threat of climate change? Either way though, the driver is survival.

[clock_tower]

This pressure has two other implications, laid out in War and Peace and War: 1. Reflux expansion: a society facing an intractable enemy will conquer or merge with more tractable neighbors. When a durable frontier forms, the societies on both sides will become organized. 2. A frontier is a potential space: sometimes, an enemy of both sides moves into the frontier and destroys or subdues both sides. Turchin's textbook example of this is the Breton-French fighting which made it possible for the Vikings to settle Normandy (and a few cities in southern Brittany).

For China, Turchin talks of how the constant confrontations with unconquerable nomads kept the civilization alive much longer than it would've otherwise endured. Toynbee thought that China should've fallen apart for good during the Three Kingdoms -- that the Han Dynasty was its universal state. China eventually stagnated, but has been the same culture since the 200s BC; the only other civilization to endure like that was ancient Egypt.

I'd really strongly advise that you look up War and Peace and War. It sounds like you understand the book's premises well, and could get a lot out of it.