I don't think Christ was a pacifist either.
Our entire judicial system is founded on Biblical precepts of justice and mercy, contrary to the Napoleonic code utilized in many Romanist countries. Our Scripturally-based judicial system assumes all men are equally guilty of sin in the abstract, including the judges and juries. Therefore a specific responsibility for a specific crime must be proven before that man is deemed guilty of that specific crime.
Christ could have been speaking of the "sword of the spirit" which is the word of God when He told his disciples "he that hath no sword, let him sell his garment, and buy one."
But the context of the verse is that Christ is well aware of the coming conflagration against Himself and all Christians by the Roman authorities. And He's warning them as well as equipping them.
Just like the Scriptures, "the sword of the spirit," protect God's children, so, too, would an iron sword protect the Christian beset by those who want to kill him.
Christ likewise tells Christians to hide, if necessary. He tells His followers not to make themselves vulnerable. He tells them to be cautious and yet fearless.
I lean towards postmillennialism. "Onward Christian soldiers..." resonates. Not that we are called to command armies and invade territories, per se, but we are instructed to preach the Gospel of Jesus Christ to all people," being "wise as serpents and harmless as doves." Christ tells us He has sent us out in the midst of wolves. He has not left us defenseless. Nor suicidal.
That is a fanciful notion of those that keep Jesus on his mom's lap.
If I may, think about the instruction to turn the other cheek. We think it's about submission and accepting mistreatment. However, in the context of the time it's an act of defiance. IOW, by turning the other cheek you would have been challenging the authority of the other person.
Also, look at how Jesus dealt with the money changers in the temple. He did not ask them nicely to stop ripping people off. He beat the heck out of them.
Finally, look at Rev. 19. When Jesus returns His robe is dipped in blood from His trampling of the "winepress of the wrath of God". Jesus then slaughters His enemies with the "sword which proceeded from the Mouth".
I lean towards postmillennialism.
Come on over to some eschatology threads and we'll show you the error of your ways. :)