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.
Now we will no longer concede so easily that anyone has the truth; the rigorous methods of inquiry have spread sufficient distrust and caution, so that we experience every man who represents opinions violently in word and deed as any enemy of our present culture, or at least as a backward person. And in fact, the fervor about having the truth counts very little today in relation to that other fervor, more gentle and silent, to be sure, for seeking the truth, a search that does not tire of learning afresh and testing anew.
Therefore, to estimate the enemy situation and to calculate distances and the degree of difficulty of the terrain so as to control victory are virtues of the superior general.
When someone asked Abraham Lincoln, after he was elected president, what he was going to do about his enemies, he replied, "I am going to destroy them. I am going to make them my friends."
All people should disclose whether they submit to Allah or not. Those who are against us are our enemies and must be fought. That includes people who call themselves Muslims but who don't lead their lives as such - people who drink, who don't pray, who don't fast, who have constantly changing partners and who are unable to recite the Koran.
Never abandon the possibility of attack. Attack even from a position of inferiority, to disrupt the enemy's plans. This often results in improving one's own position.