The second question is how to achieve such an optimal objective. Sun Tzu sorted out all methods based on their advantages and disadvantages. That is, a measurement for the objective. It is ranked based on their advantages and disadvantages. He made the following distinction between these four levels. This classic section is also very familiar to us. It is the highest strategy is by stratagem, the next best is by diplomacy, the next in order is attacking the enemy's army in the field, and the worst is besieging a walled city. The strategy of besieging a city is acted against one’s will. That’s to say, the best method of achieving this objective is by stratagem first, here “mou” means stratagem then is by diplomacy Here “jiao” means diplomacy, and “fabing” here means attacking the enemy in the field. because the city wall is solidly built, besieging a walled city will naturally result in great loss. It would be extremely costly. Sun Tzu thought it was the worst strategy, and was acted against one’s will Using massive forces as the backup, winning by stratagem and diplomacy Can the strategies help us achieve the optimal goal of breaking the enemy's resistance without fighting? For example, with the upgrading of China's international economic status our great power consciousness and great country status is upgrading. But the upgrading makes some of the previous hegemony countries in the world get upset. So they begin to make troubles to prevent our country from developing. For example, in our country, the troubles are the issues of independence of Taiwan and Tibet, and the separation of nationalities in Xinjiang . Behind all these issues exists American’s intervention. Why does America interpose in these issues undermining our relatively stable domestic political situation? Actually America adopts the strategy of winning by stratagem , making our country politically divided, so as to impede our rapid development. So if winning by stratagem and diplomacy is correctly adopted, to a country achieving the objective of complete victory, it is actually a very clever strategy. This is winning by stratagem and diplomacy After making the distinction of the four levels, as to sheer attacking the enemy in the field, Sun Tzu, based on the military strengths of both sides, made another detailed distinction. And we can see from the distinction, in order to break the enemy's resistance without fighting and achieve the optimal objective of complete victory, both of the strategies can be adopted. The strategy of attacking the enemy in the field can also be adopted. But on what occasion can it be adopted? Let’s look into his further explanation. If our forces are ten to the enemy’s, to surround them, if five to one, to attack them If twice as numerous, to divide our army into two,if equally matched, we can offer battle If slightly inferior in numbers, we can avoid the enemy, if quite unequal in every way, we can flee from them “If our forces are ten to the enemy’s, to surround them” means that If my forces are ten times to the enemy’s, when I besiege the city, I will closely surround it . With such preponderant forces and the enemy can’t get any reinforcements, the enemy will lack food and water after being surrounded for a long time, hence the enemy will soon surrender without being attacked. So if you are absolutely advantageous in military strength, ten times Sun Tzu thought greater than the enemy, we can achieve the ideal objective of breaking the enemy's resistance without fighting and capturing the whole city. This is Sun Tsu’s detailed distinction of stratagems. As to the following distinctions, let’s briefly talk about the implication. “if five to one, to attack him”, it means if my forces are five times to the enemy’s, I will surround them, but not closely so as to make the enemy surrender completely. And we can attack, or besiege the city. With five times to the enemy’s, we can be ever-victorious. if twice as numerous, it would be better to attack the enemy's army in the field rather than besiege the city. the fourth level is if we are equal in strength, we can divide the enemy. If we are equal in strength, here, “xiangruo” means fairly equal, then we should try to divide the enemy so as to make the enemy be divided into ten parts, but our strength remain undivided and create a situation of using more people to fight in local battlefield . If we are equal in strength, we can divide the enemy. This idea is related to a very important aspect of Sun Tzu’ thought on using the strong points to defeat the weak points. simply means “using the many to defeat the few” This point is reflected in our patriotic movies, from which we can see many of the tactics used by our army reflect this idea, thus, using the many to defeat the few and using the strong points to defeat the weak points. when both sides are equal in strength, and if the enemy can be divided an absolute situation of using the many to defeat the few and using the strong points to defeat the weak points can still be created in local battlefield. This is the fourth level. On fifth level, Sun Tsu said that if inferior in numbers, we can defend. If we are inferior in numbers then we should if we are not absolutely advantageous , rely on the solidly-built city- wall and steep terrain to defend rather than attack. The last is if quite unequal, we can flee from the enemy. quite unequal here means that we are in a disadvantageous situation If we are in a disadvantageous situation, we should try to avoid them in order to stage a comeback. This is Sun Tsu’s specific interpretations of attacking the enemy army in the field on the third level. This is the main idea of Attacking by Stratagem. Here we should first emphasize that as to attacking by Stratagem, he stressed you should have a sufficient ambition. This is on the strategic level, but on the tactical level Sun Tzu dialectically changed his view. For example, in the fourth piece of wring. namely, Tactical Disposition, At the very beginning of this piece of writing, Sun Tzu said that skillful fighters must be good defenders first Being good at defending is stressed on the strategic level. you must be good at defending firstly. Defending , remaining invincible, and then planning to strive for the victory on tactical level. So we must distinguish attacking from defending. According to Sun Tsu there is a difference between strategic level and tactical level. Let’s call it a day.