And He will judge between the nations,
And will [d]render decisions for many peoples;
And they will hammer their swords into plowshares and their spears into pruning hooks.
Nation will not lift up sword against nation,
And never again will they learn war. (Isaiah 2:4)
Notice here that “he” will judge the nations. Who is “he” referring to? From the previous verse it seems to be talking about God, but it also appears to be talking about the earthly ruler. As Christians we have no problem accepting that the Messiah is both God and man, which fits well with this passage.
In that day there will be no more war, because God will be able to directly resolve international disputes with both justice and power. People will have no more fear of other countries, and therefore the worlds weapons will be dismantled.
One final note is that the last line of this verse causes a slight problem for my eschatology: it says that “never again will they learn war.” Yet the book of Revelation indicates that many of them will prepare for battle against Jerusalem one more time at the end of the millennium (Revelation 20:8). At this time I am not sure how to resolve this apparent contradiction.