"It is the duty of Christians to seek peace with all men on principles of righteousness. In accordance with the spirit and teachings of Christ they should do all in their power to put an end to war.
The true remedy for the war spirit is the gospel of our Lord. The supreme need of the world is the acceptance of His teachings in all the affairs of men and nations, and the practical application of His law of love. Christian people throughout the world should pray for the reign of the Prince of Peace."
This is a rather broad, and even arguably weak statement about the Christian and his posture toward the reality of war in a fallen world. The emphasis on praying and working for peace ultimately is of course proper, as that is where the kingdom of God is headed--the grand Isaianic vision of the nations beating swords into plowshares. However, on the way there, in a fallen world only gradually being transformed by the gospel, evil will flare up from time to time and threaten the (civically) innocent and vulnerable with violence. In this case, it is certainly the individual Christian's duty in certain situations to use force to protect life.
More complex issues arise in consideration of the use of national forces and arms, especially when it comes to global affairs. Certainly a standing military is biblical and utterly necessary for national defense. There may also be legitimate criteria for initiating Just War, however, it is my personal and rather tentative position for now that the Scriptures teach a more non-interventionist view of the role of national armed forces. Greg Bahnsen and Vern Poythress have written helpfully about these matters in various places.
This section of the BF&M comes close to sounding unbiblically pacifistic by its omissions, except for its reference in the proof texts to Luke 22:36 (which is quickly qualified by a further reference to v. 38 in which Jesus responds to His disciples to the effect that "two swords" is [more than] enough). However, this section's heavy emphasis on the value of peace is certainly biblical.
