Every Christian longs for the day when this sorry world will be put completely to rights. One of the features of that day will be the destruction of our weapons, their transformation to peaceful use, and we will shut down the Naval Academy and West Point, their services being no longer required. As I said, every Christian longs for this day.
"And he shall judge among the nations, and shall rebuke many people: and they shall beat their swords into plowshares, and their spears into pruninghooks: nation shall not lift up sword against nation, neither shall they learn war any more" (Is. 2:4).
"Beat your plowshares into swords, and your pruninghooks into spears: let the weak say, I am strong" (Joel 3:10).
"And he shall judge among many people, and rebuke strong nations afar off; and they shall beat their swords into plowshares, and their spears into pruninghooks: nation shall not lift up a sword against nation, neither shall they learn war any more" (Micah 4:3).
But Christians who long for this day are not "partially pacifist." Nancy cooks well-balanced and delicious meals for me, and veggies are of course a part of that. I eat them too, but this does not make me a "partial vegetarianism." Vegetarianism is a position defined, not by the presence of vegetables, but by the absence of meat. Pacifism is not the exaltation of peace. If that were the case, every Christian would be a pacifist because we serve the Prince of Peace. Of the increase of His government there will be no end. Pacifism is the insistence that war and/or violence are never options, and this means that at bottom pacifism is sentimentalist confusion. They don't get everything wrong, because peace is desirable under many conditions, and peace is the final telos in God's story for this world. But what it does mean is that what is distinctively pacifist is fundamentally confused.
This means that Christians who love mercy, because they love the God of all mercy, will love that mercy in a way consist with all the Scriptures, and not just certain cherry-picked passages. As demonstrated earlier, God Himself is a great warrior, and reveals Himself to us as such. Throughout Scripture, being a warrior is not considered to be a profession as pursued by prostitutes, or cutpurses, or idol manufacturers. A warrior can be godly or ungodly in just the same way that a merchant can be, or a weaver, or a cook. It is a profession made necessary by the fall, which cookery is not, but it is described throughout Scripture as an honorable profession. "Now Naaman, captain of the host of the king of Syria, was a great man with his master, and honourable, because by him the LORD had given deliverance unto Syria: he was also a mighty man in valour, but he was a leper" (2 Kings 5:1). Naaman was a pagan military man, mighty in battle, and he was honorable.
"Blessed be the LORD my strength, which teacheth my hands to war, and my fingers to fight" (Ps. 144:1).
In the New Testament, we have a different state of affairs. The gospel is sent out into all the nations, in order to transform those nations. One of the tasks of the gospel is therefore to transform the militaries of those nations, and it will do this the same way the gospel transforms everything else. Salt and light, leaven in the loaf. What would you think of a Christian who said he was going to transform the film industry, and that his means for doing so would be by never having anything to do with it?
The way God will transform the military is by means of numerous Christians in the military. During my time on my second submarine (the USS Ray), in the last two years of my hitch, about 10 percent of the crew either came to Christ, or their commitment to Christ became open. At the beginning of those two years, I and one other guy, a nuke from back aft, were the only open Christians on board. When I was leaving the Navy, I had an "exit interview" with the captain (who became a Christian later, I understand), and he told me that the morale of the entire ship had been transformed. Ten percent of the crew affected far more than ten percent of the crew. This is how it is supposed to work.
When military men in the New Testament come face to face with the claims of Christ, this is the kind of thing they are told. Keep your nose clean, don't do anything outrageous, and serve Christ faithfully. "And the soldiers likewise demanded of him, saying, And what shall we do? And he said unto them, Do violence to no man, neither accuse any falsely; and be content with your wages" (Luke 3:14). "Do violence to no man" here does not refer to a requirement that they refuse to do their jobs as soldiers. After all, he says that they should be content with their wages, which assumes that they will continue to receive them. "Do violence to no man" is rendered by the ESV and NASB as "extort money from no one." In other words, the ethic required of all Christians at all times is required of Christians in the military. Individual Christian in the military have to be trained and prepared by the Church to insist on it.
We see the same realities in Christ's praise of the centurion, the highest words of praise that ever came from the Lord's lips during the course of his ministry. And He was talking about a soldier in the pagan army of the beast of Rome. "When Jesus heard it, he marvelled, and said to them that followed, Verily I say unto you, I have not found so great faith, no, not in Israel"(Mt 8:10).
I have not yet talked about how decisions to go to war need to be made. Obviously wars have been occasions of very great injustices indeed, and this means that biblical principles must be brought to bear there. This is what Augustine's famous just war theory was intended to do. If we want wars to be declared righteously, we need Christians being salt and light in Congress. They should know what jus ad bellum means because they are the ones responsible to declare war. If we want wars to be fought righteously, we need Christians being salt and light in the military. They need to know what jus in bello means. Just grounds for going to war are one thing, and just conduct in war is another. Obedience to these scriptural standards is conducted in different spheres.
Put another way, just war theory is very little help to an eighteen-year-old recruit. What must he have instead? He should have a strong walk with Christ, he should know that he must never exhort money, he should not grumble about his paycheck like everybody else does, he must never rape women, and so forth. But as a born-again ground-pounder is not told that he must become well-versed in geo-politics, read 58 books on inter-libarary loan, and establish himself in Augustine's just war theory, before he personally can decide to go on a given mission. The application of putting just war theory into the hands of everyman is American individualism run amok.