Since war is not an act of senseless passion but is controlled by its political object, the value of this object must determine the sacrifices to be made of it in magnitude and also in duration. Once the expenditure of effort exceeds the value of the political object, the object must be renounced and peace must follow. (Book One, Chapter Two, p. 92).
Sun Tzu is equally adamant:
Victory is the main object in war. If this is long delayed, weapons are blunted and morale depressed. When troops attack cities, their strength will be exhausted. (The Art of War, Book II, Par. 3)
When the army engages in protracted campaigns the resources of the state will not suffice. (The Art of War, Book II, Par. 4)
Thus, while we have heard of blundering swiftness in war, we have not yet seen a clever operation that was prolonged. (The Art of War, Book II, Par. 6)
For there has never been a protracted war from which a country has benefited. (The Art of War, Book II, Par. 7)
Hence, what is essential in war is victory, not prolonged operations. And therefore the general who understands war is the Minister of the people’s fate and arbiter of the nation’s destiny. (The Art of War, Book II, Par. 21)
Interestingly, in the Griffith translation of The Art of War, there is the following annotation following Par. 21:
Ho Yen-his: The difficulties in the appointment of a commander are the same today as they were in ancient times. [Griffith notes that Ho wrote this about 1050 A. D.]
It appears obvious that the difficulties in the appointment of a commander are the same today in 2013 as they were in ancient times.