What does that mean, exactly? Is it a moral absolute?
I wouldn’t say its a moral absolute just because there is so much room for personal interpretation. Even when it comes to loving those closest to us, people disagree on the best way to do that.
Also, the commandment to love your enemies has to be balanced with the commandment to love your neighbour, etc. Our obligations towards those closest to us might conflict with the obligations we have to people we are less responsible for, e.g. our enemies in a war.
But one thing it means for sure is what we should remember that these people who are on the opposite side of a conflict are children of God like we are, and that God loves them and desires that they be saved. We are also forbidden to hate anyone, even our enemy. We might still go to war with them if necessary, but never out of anger or a desire for vengeance. We have to sincerely do our best to balance our duties towards ourselves, our families, our countrymen, and the duty to love the enemy.
Yes it is a moral absolute. However, love is not an emotion, it is a choice. It is the choice to will what is best for a person, and the best scenarios for all people are mutually interdependent, not mutually exclusive.
For example, “the best” for someone who is making war on me is not that he be victorious, but that he turns to God. It may include material prosperity, but it will definitely include spiritual prosperity. We may not know exactly what scenario would be best for someone, but it is enough to simply make a general act of the will for “the best” and leave it in God’s hands.
Jesus commanded us to love our enemies - he didn’t suggest it. Yes, we must love our enemies at all times and in all circumstances.
And he never said we have to*** like ***them…