One of the really key things to grasp from studying military/political theory is how counter-intuitive the perception of strength and weakness is.
When a military force takes its strongest unit out of reserve and dedicates it to a battle, it is demonstrating weakness and insecurity. It is losing initiative and being forced to act reactively, rather than remaining flexible - it is a fundamentally defensive behaviour to assault the enemy with a great force. Politically, to engage in strict repression of class enemies, to mercilessly destroy those who threaten your class dictatorship, is something done when your power is, in fact, threatened - when it is weak.
Conversely, it is a sign of great strength to show restraint. Fighting with desperation is done by the desparate, by those who are being forced to act a given way by their enemies. When overmatching the enemy, it is always better to take your time and act deliberately, to force them to battle only on your terms. Attacking the enemy piecemeal, defeating them slowly in detail, implies the ability to force the enemy to act and divide themselves at your will. If you are not seriously threatened, then there is no need to dedicate yourself entirely to a given battle, and you would do much better to avoid doing so.
This is, to the uninitiated, counter-intuitive. People see great shows of force and percieve them as strength. People see restraint and perceive it as a lack of will. People idolise times of great desperation because all they see is the immense action that resulted - and they spurn times of strength and security, because they see a lack of action. Through one means or another, they arrive at a common flaw: the fetishism of defeat.
