Accustomed as we are to think of China as the greatest peace-loving nation on earth, we are in some danger of forgetting that her experience of war in all its phases has also been such as no modern State can parallel. Her long military annals stretch back to a point at which they are lost in the mists of time. She had built the Great Wall and was maintaining a huge standing army along her frontier centuries before the first Roman legionary was seen on the Danube. What with the perpetual collisions of the ancient feudal States, the grim conflicts with Huns, Turks and other invaders after the centralization of government, the terrific upheavals which accompanied the overthrow of so many dynasties, besides the countless rebellions and minor disturbances that have flamed up and flickered out again one by one, it is hardly too much to say that the clash of arms has never ceased to resound in one portion or another of the Empire.
No less remarkable is the succession of illustrious captains to whom China can point with pride. As in all countries, the greatest are fond of emerging at the most fateful crises of her history. Thus, Po Ch`i stands out conspicuous in the period when Ch`in was entering upon her final struggle with the remaining independent states. The stormy years which followed the break-up of the Ch`in dynasty are illuminated by the transcendent genius of Han Hsin. When the House of Han in turn is tottering to its fall, the great and baleful figure of Ts`ao Ts`ao dominates the scene. And in the establishment of the T`ang dynasty,one of the mightiest tasks achieved by man, the superhuman energy of Li Shih-min (afterwards the Emperor T`ai Tsung) was seconded by the brilliant strategy of Li Ching. None of these generals need fear comparison with the greatest names in the military history of Europe.
In spite of all this, the great body of Chinese sentiment, from Lao Tzu downwards, and especially as reflected in the standard literature of Confucianism, has been consistently pacific and intensely opposed to militarism in any form. It is such an uncommon thing to find any of the literati defending warfare on principle, that I have thought it worth while to collect and translate a few passages in which the unorthodox view is upheld. The following, by Ssu-ma Ch`ien, shows that for all his ardent admiration of Confucius, he was yet no advocate of peace at any price: —
Military weapons are the means used by the Sage to punish violence and cruelty, to give peace to troublous times, to remove difficulties and dangers, and to succor those who are in peril. Every animal with blood in its veins and horns on its head will fight when it is attacked. How much more so will man, who carries in his breast the faculties of love and hatred, joy and anger! When he is pleased, a feeling of affection springs up within him; when angry, his poisoned sting is brought into play. That is the natural law which governs his being…. What then shall be said of those scholars of our time, blind to all great issues, and without any appreciation of relative values, who can only bark out their stale formulas about “virtue” and “civilization,” condemning the use of military weapons? They will surely bring our country to impotence and dishonor and the loss of her rightful heritage; or, at the very least, they will bring about invasion and rebellion, sacrifice of territory and general enfeeblement. Yet they obstinately refuse to modify the position they have taken up. The truth is that, just as in the family the teacher must not spare the rod, and punishments cannot be dispensed with in the State, so military chastisement can never be allowed to fall into abeyance in the Empire. All one can say is that this power will be exercised wisely by some, foolishly by others, and that among those who bear arms some will be loyal and others rebellious. 
The next piece is taken from Tu Mu’s preface to his commentary on Sun Tzu: —
War may be defined as punishment, which is one of the functions of government. It was the profession of Chung Yu and Jan Ch`iu, both disciples of Confucius. Nowadays, the holding of trials and hearing of litigation, the imprisonment of offenders and their execution by flogging in the market- place, are all done by officials. But the wielding of huge armies, the throwing down of fortified cities, the hauling of women and children into captivity, and the beheading of traitors — this is also work which is done by officials. The objects of the rack and of military weapons are essentially the same. There is no intrinsic difference between the punishment of flogging and cutting off heads in war. For the lesser infractions of law, which are easily dealt with, only a small amount of force need be employed: hence the use of military weapons and wholesale decapitation. In both cases, however, the end in view is to get rid of wicked people, and to give comfort and relief to the good….
Chi-sun asked Jan Yu, saying: “Have you, Sir, acquired your military aptitude by study, or is it innate?” Jan Yu replied: “It has been acquired by study.”  “How can that be so,” said Chi-sun, “seeing that you are a disciple of Confucius?” “It is a fact,” replied Jan Yu; “I was taught by Confucius. It is fitting that the great Sage should exercise both civil and military functions, though to be sure my instruction in the art of fighting has not yet gone very far.”
Now, who the author was of this rigid distinction between the “civil” and the “military,” and the limitation of each to a separate sphere of action, or in what year of which dynasty it was first introduced, is more than I can say. But, at any rate, it has come about that the members of the governing class are quite afraid of enlarging on military topics, or do so only in a shamefaced manner. If any are bold enough to discuss the subject, they are at once set down as eccentric individuals of coarse and brutal propensities. This is an extraordinary instance in which, through sheer lack of reasoning, men unhappily lose sight of fundamental principles.
When the Duke of Chou was minister under Ch`eng Wang, he regulated ceremonies and made music, and venerated the arts of scholarship and learning; yet when the barbarians of the River Huai revolted,  he sallied forth and chastised them. When Confucius held office under the Duke of Lu, and a meeting was convened at Chia-ku,  he said: “If pacific negotiations are in progress, warlike preparations should have been made beforehand.” He rebuked and shamed the Marquis of Ch`i, who cowered under him and dared not proceed to violence. How can it be said that these two great Sages had no knowledge of military matters?
We have seen that the great Chu Hsi held Sun Tzu in high esteem. He also appeals to the authority of the Classics: —
Our Master Confucius, answering Duke Ling of Wei, said: “I have never studied matters connected with armies and battalions.”  Replying to K`ung Wen-tzu, he said: I have not been instructed about buff-coats and weapons.” But if we turn to the meeting at Chia-ku, we find that he used armed force against the men of Lai, so that the marquis of Ch`i was overawed. Again, when the inhabitants of Pi revolted, the ordered his officers to attack them, whereupon they were defeated and fled in confusion. He once uttered the words: “If I fight, I conquer.”  And Jan Yu also said: “The Sage exercises both civil and military functions.”  Can it be a fact that Confucius never studied or received instruction in the art of war? We can only say that he did not specially choose matters connected with armies and fighting to be the subject of his teaching.
Sun Hsing-yen, the editor of Sun Tzu, writes in similar strain: —
Confucius said: “I am unversed in military matters.”  He also said: “If I fight, I conquer.” Confucius ordered ceremonies and regulated music. Now war constitutes one of the five classes of State ceremonial,  and must not be treated as an independent branch of study. Hence, the words “I am unversed in” must be taken to mean that there are things which even an inspired Teacher does not know. Those who have to lead an army and devise stratagems, must learn the art of war. But if one can command the services of a good general like Sun Tzu, who was employed by Wu Tzu-hsu, there is no need to learn it oneself. Hence the remark added by Confucius: “If I fight, I conquer.”
The men of the present day, however, willfully interpret these words of Confucius in their narrowest sense, as though he meant that books on the art of war were not worth reading. With blind persistency, they adduce the example of Chao Kua, who pored over his father’s books to no purpose,  as a proof that all military theory is useless. Again, seeing that books on war have to do with such things as opportunism in designing plans, and the conversion of spies, they hold that the art is immoral and unworthy of a sage. These people ignore the fact that the studies of our scholars and the civil administration of our officials also require steady application and practice before efficiency is reached. The ancients were particularly chary of allowing mere novices to botch their work.  Weapons are baneful  and fighting perilous; and useless unless a general is in constant practice, he ought not to hazard other men’s lives in battle.  Hence it is essential that Sun Tzu’s 13 chapters should be studied.
Hsiang Liang used to instruct his nephew Chi  in the art of war. Chi got a rough idea of the art in its general bearings, but would not pursue his studies to their proper outcome, the consequence being that he was finally defeated and overthrown. He did not realize that the tricks and artifices of war are beyond verbal computation. Duke Hsiang of Sung and King Yen of Hsu were brought to destruction by their misplaced humanity. The treacherous and underhand nature of war necessitates the use of guile and stratagem suited to the occasion. There is a case on record of Confucius himself having violated an extorted oath,  and also of his having left the Sung State in disguise.  Can we then recklessly arraign Sun Tzu for disregarding truth and honesty?