A mysterious Chinese warrior philosopher compiled this book over 2,000 years ago. It was translated into English by an author named, Thomas Cleary, who holds a PhD in East Asian Languages and Civilizations from Harvard University. He is the translator of various works in Buddhist, Taoist, and I Ching studies.
It is still the most prestigious and influential book today for study by politicians and military strategists everywhere. The main theme of this book is to "To Win Without Fighting Is Best." It gets a large part of its background from the Taoist philosophy. Sun-Tzu concentrates on the political side with a set of guidelines on the operational level for the general to follow. Where the operational level is concerned, Sun-Tzu puts forth many principles on the operational and political level.
The Art of War spans about 13 chapters, taking up less than a hundred pages in its English translation. Sun-Tzu is a book of principles and maxims. When comparing the relative strengths of the offense and defensive positions, Sun-Tzu maintains that the defensive is the stronger position: "It is easier to hold ground than take it. It follows that the defense is easier than the attack, assuming both sides have equal means." Sun-Tzu also maintains this in his principles of what to attack: "worst of all is to besiege their city fortifications" and "For undefeatability, defend." It's understood that the defender has a greater incentive to fight then an army far from its own borders. It also states that the actual war itself must be left in the hands of the military leaders rather then the political leaders. As Sun-Tzu comments: "So a lord may harm the armies in three ways... By not knowing the armies' affairs yet interfering with the armies policies; the armies' warriors will be leery." Policy, of course, will not extend its influence to operational details. Political considerations do not determine the posting of guards or the employment of patrols.