Asoka abandoned wars as a solution after the Kalinga war. His speech to the soldiers after the war tells us all:

”  Soldiers, great military power carries great responsibility. Such power can be dangerous in the hands of an arrogant ruler and an arrogant country. So far, we have used this power to destroy, kill and conquer, but not to improve the lot of man. We must humanize this brute power or it will turn us into savages.’
He paused.
‘Today, I declare that Magadha will no longer resort to aggressive wars. If life offers nothing but misery, wars are glorious. Even cannibalism is desirable. But when we look at the faces of our children, the beauty of this splendid Creation, and think of our short time on this earth, we know life is too valuable. We have to change our old ideas. War destroys all human feelings, brutalizes men, women and even children. It destroys past, present and future. It forces man to live in fear and rage. It is a deliberate cruelty against life. We delude ourselves if we call ourselves civilized, and the enemy barbarian. So I say to you, henceforth we shall not use military force to impose our way of life, our beliefs, and our system of government on others.’
Every soldier gasped.
Asoka continued, ‘How will we resolve our disagreements then! By diplomacy, negotiations, even sabotage and subversion. But above all by patience.’
Some of the soldiers registered surprise as Asoka went on. ‘Conquest! Glory! Honor! Medals! They are good for making great speeches. They resonate in us for a few moments. But after the applause has died down, a deafening silence begins. What glory will bring back the dead? What medal will restore a soldier’s severed hands to lift his child in embrace? What speech can clamp together a soldier’s broken manhood? Repair the disfigurement of his mind? What gold medal will warm the young widows’ lonely bed?
‘Truth is brutal and I will not lie. Acting hand in hand, religion and state have glorified wars and made martyrs of the dead. Both the state and religion seek power through wars, and human life does not matter. I should know.’
‘The truth is that the rainbow of war’s glory has been painted with the blood of our youth, and the tears of our children and widows.’
Then he looked at the faces of soldiers’ sitting before him, and said, ‘What beauty, soldiers, I ask you, can I show you in non-existence?’
‘It is a momentous day for Magadha. Our children must do better. ’  ”

To a lukewarm ovation, he quietly slipped out by the back door. Most of the soldiers could not shake off the conviction that wars were ordained by God, essential to the country’s glory, and that wars were the flower of their manhood. Slowly, the crowd dispersed. On leaving the Hall, an old former army officer lifted his skullcap and mumbled, ‘First he becomes an atheist and now he gives up war! I tell you, this empire is going to fall.’
Forgetting his own age, he looked up at the sky. ‘God! I don’t want to live to see that day!’