As they were during the Cold War, urban population centers remain the most likely targets of a nuclear attack. Now, however, an attack may come without warning from an unknown enemy, to achieve unclear motives.
A king may be a tool, a thing of straw; but if he serves to frighten our enemies, and secure our property, it is well enough; a scarecrow is a thing of straw, but it protects the corn.
Our faith in others betrays that we would rather have faith in ourselves. Our longing for a friend is our betrayer. And often with our love we want merely to overcome envy. And often we attack and make ourselves enemies, to conceal that we are vulnerable.
Your enemy shall ye seek; your war shall ye wage, and for the sake of your thoughts! And if your thoughts succumb, your uprightness shall still shout triumph thereby!
So the principles of warfare are: Do not depend on the enemy not coming, but depend on our readiness against him. Do not depend on the enemy not attacking, but depend on our position that cannot be attacked.