Love your enemies, don't kill them?

Saw a bumpersticker over lunch today. It said

"When Jesus said love your enemies, I'm pretty sure he meant don't kill them."

How beautifully simplistic and naive. In my book, the rules change when your enemy is trying to kill you and/or yours.

Let's give another, more balanced quote:

EcclesiastesChapter 3

1. There is an appointed time for everything, and a time for every affair under the heavens.
2. A time to be born, and a time to die; a time to plant, and a time to uproot the plant.
3. A time to kill, and a time to heal; a time to tear down, and a time to build.
4. A time to weep, and a time to laugh; a time to mourn, and a time to dance.
5. A time to scatter stones, and a time to gather them; a time to embrace, and a time to be far from embraces.
6. A time to seek, and a time to lose; a time to keep, and a time to cast away.
7. A time to rend, and a time to sew; a time to be silent, and a time to speak.
8. A time to love, and a time to hate; a time of war, and a time of peace. .

The Byrds put it quite beautifully to music.