My first reaction to this question is ‘no: that’s what causes wars.’ But on reflection I think this needs qualifying.
If you say ‘I am right to kill innocent people in the cause of my religion or ethnic group or country’ that is going to cause violence and counter violence and counter counter violence, and so on ad nauseam.
But what if you say ‘It is always right to love your enemies’? Would that be likely to cause a war? If some other group of people decided to try to make you change your mind by force they would meet with no resistance – hence there would be no war unless others tried to defend you, in which case they would not be loving their enemy and, paradoxically, would not be agreeing to your statement of belief.
The complication comes in when your enemies are threatening your own family and friends. Or threatening you when you have a family that depends on you. Then, I feel, one must make a stand. You must try to defeat your enemies but do so without gratuitous violence and with unbounded mercy, i.e. still love them. If everyone forced to fight did so in this way, then war in general would gradually fade away. It might take a long time but at least the practice of war would be less barbaric in the meantime.
Author, 2077 AD