The way I look at it, we can beat our swords in to plowshares when we don't need them any more. The prophecy is a promise, not an instruction. I believe there is such a thing as a just and "good" fight. The day we don't need weapons is the day there are no more bullies on the earth.
One bible story I pondered for a long time was a small group of people who found a remote valley, lush and untouched. In that wonderful place, the people prospered...and got soft. They were taken over by the next roving band of bandits. (Judges 18).
Also, JW's aren't the only pacifists. Check out the Quakers. They are active pacifists rather than just neutral observers. They have a school in Lebanon dedicated to bringing together historical enemies.