Violence can sometimes bring about peace, as when you defeat and destroy an enemy in battle and thereby bring peace to the land. It is pointless trying to get barbarians to 'understand'. They only understand one thing: who is stronger ? But such peace may not be long-lasting as the defeated enemy may gather strength and again return to create more havoc. But generally it is true. Long-lasting peace cannot be achieved through violence. Understanding is needed. As far as internal struggles are concerned, the saying is 100% true. Internal conflict can only be resolved through right understanding and right conduct.