I do not know with what weapons World War III will be fought, but World War IV will be fought with sticks and stones. Letter to Harry S. Truman.

風　Swift as the wind
林　Quiet as the forest
火　Conquer like the fire
山　Steady as the mountain

You cannot simultaneously prevent and prepare for war.

The loud little handful will shout for war. The pulpit will warily and cautiously protest at first…The great mass of the nation will rub its sleepy eyes, and will try to make out why there should be a war, and they will say earnestly and indignantly: "It is unjust and dishonorable and there is no need for war." Then the few will shout even louder…Before long you will see a curious thing: anti-war speakers will be stoned from the platform, and free speech will be strangled by hordes of furious men who still agree with the speakers but dare not admit it ... Next, statesmen will invent cheap lies, putting blame upon the nation that is attacked, and every man will be glad of those conscience-soothing falsities, and will diligently study them, and refuse to examine any refutations of them; and thus he will by and by convince himself that the war is just, and will thank God for the better sleep he enjoys after this process of grotesque self-deception.

Victorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win.

Speed is the essence of war. Take advantage of the enemy's unpreparedness; travel by unexpected routes and strike him where he has taken no precautions.

This topic brings me to that worst outcrop of the herd nature, the military system, which I abhor. That a man can take pleasure in marching in formation to the strains of a band is enough to make me despise him. He has only been given his big brain by mistake; a backbone was all he needed. This plague-spot of civilisation ought to be abolished with all possible speed. Heroism by order, senseless violence, and all the pestilent nonsense that goes by the name of patriotism — how I hate them! War seems to me a mean, contemptible thing: I would rather be hacked in pieces than take part in such an abominable business.

There is no instance of a nation benefitting from prolonged warfare.

Now I want you to remember that no bastard ever won a war by dying for his country. He won it by making the other poor dumb bastard die for his country. (June, 1944)

It is said that if you know your enemies and know yourself, you will not be imperilled in a hundred battles; if you do not know your enemies but do know yourself, you will win one and lose one; if you do not know your enemies nor yourself, you will be imperilled in every single battle.