It seems that way to often people use Jesus as a "Prince of Peace".
The reasons I have seen for this idea are this:
1. Justifying leftist politics with that "Old time religion"
2. Doing what the Right does by hiring Jesus as their celebrity endorsement
(Thats all of the justifications i could think of now>
In Matthew 10:34 it says:
"Do not suppose that I have come to bring peace to the earth. I did not come to bring peace, but a sword."
So maybe the sword is peace, hitting back to that (overly used) "1984" speak: War is Peace