That’s what those who want to justify killing for “the right reason” want you to believe. I believe it was thou shall not kill, period. The young men who are trained to be able to kill by those who should know better have less culpability, IMHO, but yes, that is what I believe. So the same Jesus that said to turn the other cheek said to sell your cloak for a sword? Something’s wrong with that picture, or interpretation, or translation. And I am not claiming it would be easy, what’s easy is lashing out violently in return, it’s hard to keep control and put your trust in the Creator who has your eternal life in his hands.