DTM.9:2 - Problem

Protection is often represented only by how much it removes. That omits the process that produces the response, what it costs, which useful activity it restricts and how the remaining variants change its future conditions.

An immediate decrease can therefore coexist with later release of another variant, loss of useful work or persistent restriction after the initiating condition has disappeared. The protective action can become part of the problem without ceasing to have a protective effect.