Enmity is inescapable. Conflict is in the cards. Good and evil cannot coexist, regardless of what the bumper stickers tell us. God has infused enmity into the order of the world, or rather, it should be said into the disorder of the world. God is not a God of disorder, but of order. It is Christ or chaos. The two are mutually exclusive. They cannot kumbaya. There will be warfare. There armies may not always be actively firing at each other, but they are always maneuvering, planning, and positioning themselves for their next assaults.
So, they may not always be exchanging blows, but they are always preparing for the next strike. And if something is worth hitting over, it is worth hitting hard over. There is no sense is soft hitting. There is no mercy in being milquetoast. Swift and severe often ends in less overall devastation than slow and subtle. If you unsheathe your sword, don't put it away until there is nothing left to swing at. Cut and hack most resolutely, and then remember to clean your sword. (Pilgrim's Progress, The Chronicles of Narnia)
"The unforgivable crime is soft hitting. Do not hit at all if it can be avoided; but never hit softly." — Theodore Roosevelt
Casualties are reduced when contacts are made to count. An efficient first strike can sometimes be sufficient enough to eliminate the need for future engagement. If you can convince the enemy to stand down, you can save more of your enemies lives than you could have by convincing them that they had a chance.
"If you decide to fight, you also have to decide to win." — Luther (movie: 2003)
You cannot fight half-heartedly. If something is worth fighting about, it is worth fighting as hard as you can about.
"Believe that you can whip the enemy, and you have won half the battle." — J. E. B. Stuart
You should not swing unless you think you can take him and then, swing away. But don't timidly tap your opponent. Either give them the dignity of loving them well as an enemy by opposing them ferociously or give them an apology for having previously opposed them and love them by becoming their friend. If they should be opposed, then oppose them well. That is loving your enemy. If they should not be opposed, stop opposing them and ask them for their forgiveness for having done so before. That is also loving your enemy.