Consider the american civil war. The war was stalemated until northern generals Ulysses S Grant, William Tecumseh Sherman, and Philip Sheridan adopted the policy of thorough. Thorough meant destroying everything. Every house and every barn was burned. Every farm animal was killed. Fields were burned. The north won the american civil war by being mean and cruel and nasty to the civilians in the south.
People are more afraid of the bad guys than of the good guys.