Pick your battles, guidelines

Washington won Independence by evading most fights and keeping the Continental Army in tact.
Similar plans had all been executed by Alexander, Julius Caesar, and later Napoleon.
How do you know when to do what?

Sun Tsu had some guidelines:

Overpowering alone is not enough.
Only engage in battles you need to win
More important to out think than overwhelm your opponent
Always focus your strengths againt their weakness
Only attack to distract from your main objective
Deception is a key to all victory over those who oppose you
Many other tactics of The Art of War can be applied to the politics of Business. But these are only for those determined to be your opposition. Always take the high ground being amicable to all and virtuous to all ( the exception being those who oppose you)

Study and Prepare, then execute, execute, execute