Jesus said many things that must be considered in the light of tradition, Aquinas, and expediency.  Love your enemies was said before the Church was a secular power, with its own military and that of the sovereigns of Europe to support it.  Since then, Tradition has trumped Jesus.  Love your enemies has been supplanted with theories that allow for violence when it is necessary, or expedient.  And that is now the Hallowed Tradition of the One True and Unchanging Church.  

Regarding the Colt .45 Single Action Army Revolver, neither conservative nor progressive can take credit for dubbing it the "Peacemaker."  In all likelihood, that name was applied by Protestants.