When I first described pressure points and catalysts, the goal was to explain why large-scale change rarely arrives without warning. History does not shift randomly. It shifts when accumulating pressures reach limits that systems can no longer absorb. That framing remains. We now move one layer deeper — from pressure as a visible signal to constraint as the underlying mechanic.

A pressure point is not simply stress in the abstract. It is a constraint that reduces flexibility. It is a limit that narrows optionality. It appears when decisions become harder to reverse, when response time shrinks, when coordination becomes more expensive, and when substitution becomes necessary rather than optional. Pressure points mark where systems are approaching or crossing limits.