Phil Ochs wrote, "Think of all we've won with a saber and a gun/Was it worth it all?"

Excellent question! But I think that you have to ask others and not yourself. For example, those in Dachau, or the people of Manila back in '45, or those held as POWs by the Japanese, or those recently liberated from ISIS, or those in the American Revolution, or the Korean "Comfort Women", or the women and girls rescued from Boko Haram just a couple days ago, or the freed slaves in the US, or the Irish, or the American Indians who opened a big case of whump-ass on the US Army at places like the Greasy Grass and St. Clair's Defeat and the Big Hole, or Europe back in '44, or any of a number of things.

Unfortunately, unilateral violence seems to go on and on because some people are easily led by others who see violence as the only way to power. Then others must step in to prevent them or in self-defense or to liberate themselves. Unfortunately, others may see this prevention/self-defense/liberation as an opportunity to gain power themselves and so perpetuate the whole, ugly, cycle.