"I have come NOT to bring peace, BUT THE SWORD."
Paul tells us to judge just judgment, and that the GOVERNMENT IS THE SWORD OF GOD.
Assassination is perfectly moral.
"Don't imagine that I came to bring peace to the earth! No, rather, a sword. I have come to set a man against his father, and a daughter against her mother, and a daughter-in-law against her mother-in-law; a man's worst enemies will be found right in his own home! If you love your father and mother more than you love me, you are not worthy of being mine; or if you love your son or daughter more than me, you are not worthy of being mine."
I dont think Jesus is talking about killing heads of state and anyone we feel like. He is talking about people placing more value in their loved ones than in him and how brother will turn against brother when their faiths conflict...People just love to Quote that verse out of context all the time, from Satanists to criminalize christianity to those looking for excuses for violence.