All wars are won or lost before they are ever fought.
Do not engage an enemy more powerful than you. And if it is unavoidable and you do have to engage, then make sure you engage it on your terms, not on your enemy's terms.
Sweat more during peace: bleed less during war
If quick, I survive. If not quick, I am lost. This is death.
So the important thing in a military operation is victory, not persistence.
The general who advances without coveting fame and retreats without fearing disgrace, whose only thought is to protect his country and do good service for his sovereign, is the jewel of the kingdom.