On the other hand, every care must be taken not to render the enemy desperate; and, as an instance of this, Sun observes that an opponent should on no account be completely surrounded. A loop-hole of escape weakens the resolution of the general and the energy of his troops. It is interesting to notice that _moral_, or the spirit of the troops, is thus considered a determining factor in war. The Chinese are perhaps unusually affected by climatic conditions. As is well known, the umbrella was part of a soldier's equipment; and for the same reasons, the sunny side of high ground is recommended as most suitable for defence, tactical considerations permitting. The large number of bannermen in the Chinese army was out of all proportion to the service of standards in providing rallying points. The chief use of banners was to maintain the spirit of the troops. A forest of banners, held erect, gave a feeling of liveliness and security to the ranks, in the same way as a military band, and when Sun remarks that the march of an army should be calm like the forest, he is using a simile that is not inappropriate. Probably owing to the fact that the profession of arms has never been highly regarded in China, we find that the ruler of the state did not usually take the field, but employed a professional to command the army--one of the masters of war who wandered from state to state at that time with the secrets of victory to impart to the highest bidder. The question of political interference with the general in the field naturally arises under these conditions. The two sages point out, that to unite the nation under firm and just government is the business of the ruler and necessary to victory; but that the general is the best judge of the questions that arise on a distant field, and that all interference with him causes delay and disaster. War meaning ravage, it was essential that the operations should be conducted in the enemy's territory. Once there, however, a vigorous offensive is no longer advised. "At first behave with the discretion of a maiden" is the counsel of Sun. The enemy must be induced to take the initiative, and when he is worn out by marching, or makes a false move, "then," says the master, "dart in like a rabbit." Unlike the tactics of the Japanese, in whom the spirit of attack burns so strongly, those of Suntzu and Wutzu are essentially of the offensive-defensive order--manoeuvre before fighting, and non-committal until the enemy has shown his hand. The business of the general is to avoid encounter in battle until the enemy is no longer capable of offering a successful resistance.