There is nothing more Christian than war - a just war. For in waging war justly, we fight for the purposes of the Lord. Pacifism is not what Jesus taught, it is what he taught Peter in light of the crucifixion, the will of the Father to have him slain for our sins.
This war has been won, and the door opened to heaven, but on earth the victory is not always present. Though heaven is open to us, we must open earth to heaven. Become a light, become a vision of heaven to earth and fight the holy fight to defend, to love, and to die with sword and weapon in hand, and if possible, with chalice raised before posterity, before soldiers, before countrymen, and before Lords.
Despite all this, pacifism relies on others, to sin? Or to win? It is not sin to fight in a holy war for God, for land, and for family.