How does one love one's enemies? (And when?)

Luke 19-14 "But his subjects hated him and sent a delegation after him to say, 'We don't want this man to be our king.'"

Luke 19:27 "But those enemies of mine who did not want me to be king over them—bring them here and kill them in front of me."

Matthew 5:44-45 "But I tell you: Love your enemies and pray for those who persecute you, that you may be sons of your Father in heaven. He causes his sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous."

Is one necessarily one's enemy's enemy? Depending on the definition of "enemy"? What is an "enemy"?

If one loves one's enemies, are one's enemies still one's enemies? Depending on the definition of "enemy" and the timing of the love?

If the subjects had loved the king-to-be in the first place, would the king-t0-be still be their enemy? Would the king-to-be still persecute them? Would they still send the delegation? Would they still be the king's enemies? Would the king still kill them?

If the subjects had turned to love the king-to-be after having sent out the delegation, would the king still be their enemy? Would they still be the king's enemies? Would the king still kill them?

May the king, who killed his enemies, be a son of his Father in heaven?

How (and when) does one love one's enemies?