Today's psalter (Monday week III) include a canticle from Isaiah 2: 2-5. It details a vision Isaiah had at a time when the kngdom of Judah was threatened by war. It was a vision of a future time not only of peace, but of the pre-eminence of Jerusalem as a focus of peace and spiritual instruction for all nations.
This, of course, was fulfilled in the coming of Jesus, although that fulfillment won't be complete until the end of time. In the meantime, there are several ways to think about what "Mt. Zion", the hill on which Jerusalem stands, means for us.
- we could meditate on the real, physical Mt. Zion. People really do go there from all the nations of earth, on pilgrimage to visit the scenes of Our Lord's earthly life. Everyone I know who has visited the holy land is certainly inspired, even transformed by the experience.
- we could think of the Catholic Church as a new Mt. Zion, since people have come to her from all nations, and find in her "instruction in God's ways".
- we could think of the end of the world, where all will appear before God to receive judgment, and those who are saved will enter the "New Jerusalem" that is heaven. There, at least, we can be sure that all war will be at an end, swords will be plowshares, spears pruning hooks, etc.