Those who were able to cause them to surrender without out fighting were smart. This is because preservation is a key element of Sun Tzu's war. He says how it is better to preserver the enemies facilities rather than to destroy it. ("Preserving the [enemy's] state capital is best, destroying their state capital is second-best..."). This is the "true pinnacle of excellence". "Why? Isn't it better to just to eradicate your enemies completely?" you might ask. NO. This is because what is point of ruling over land that is reduced to nothing, farms that are destroyed, and survivors who now hold animosity towards you? Nothing. But if you were able to preserve all of that then now you are able to use it. Farmland, docks, and mines, are now all usable by you. You do not need to rebuild and waste time and resources doing so. He also says another interesting quote: " For this reason attaining one hundred victories in one hundred battles is not the pinnacle of excellence." Wait, what? Winning one hundred out one hundred is not true excellence? Sure you have a 100% win rate, but the consequence of those battles can and will be great and that will outweigh the benefits in the end.
So far the book is really enjoyable. There was slight confusion in a little section due to the awkward wording ( for me ) but other than that it was very informative.