In love, no absolutely not. That sounds like a justification for rape, spousal abuse, stalking, harassment, cheating, and other kinds of shitty behavior where it is neither expected nor wanted.
In war, yes. I think that war is one of the most horrific things one nation can perpetrate on another and should be exactly that.. If your goal, as a nation, is anything less than the genocide of your target nation's people, the salting of their land, and the complete eradication of their culture, then your issues can and should be solved diplomatically.
And if that is your goal, fuckin' do it.
That makes more sense. So, personal conflict rather than national conflict?
In my present state of moderate intoxication, I'd say something similar to my above point, but with the opposite statement regarding fairness. If you are unable to resolve your differences via civil discussion, then settle it with a duel with strict rules as follows.
The rules of which should be:
the field should be cleared of bystanders, excepting an impartial referee
The only weapons permitted should be flintlock, smooth bore pistols
Shooting should occur at high noon (or whatever time would give both parties equal visual impairment due to the sun)
Parties should stand twenty paces apart
Parties should fire one round each and then move an additional ten paces apart
Repeat step 4 until at least one party is dead