Engaging in a conversation with your enemy is counter productive.
You destroy your capability of dehumanization there.
You can yell slogans at them and treat them like the animals that they are.
Never treat your enemies as humans.
It might make you hesitate the next time you are about to kill them.
Depends on who it is - I imagine most characters, just like most people, have enemies, and then they have
Enemies.The former are the people who happen to be in conflict with you, for a variety of temporary reasons or for understandable or 'forgivable' reasons, such as justifiable causes, the politics of the day, accident, conflicting ideologies but similar beliefs and values, and so on. This person can be understood - putting yourself in his shoes is not hard because you are in the exact same situation, just with a different uniform and flag. You can forgive him, even if you fully intend to do your duty and kill him, because he might as well have been you.
Then there is the
FUCKING ENEMY. The type of entity that are below human, soulless, pain-and-death-deserving
SCUM. The kind that are entirely and mercilessly opposed, ideologically, practically, morally, politically and so on. The type of enemy you have no qualms about killing, whose death you enjoy, the type of entity you have no interest in understanding, because there is nothing to understand - the enemy might as well be a non-humanoid alien with far to many limbs and/or eyes to invoke any sympathy.
IMHO, having to many of either or only representatives in one camp is a bad idea - either you come off to friendly, or to hostile, and the dynamics between you and your opponents remains the same, each time.
Having said that, having the disposition to off the type 1 enemy without hesitation might be a source of RP in itself;
"I believed we understood each other..."
"We do, but war is war regardless."