The startling vision Isaiah offers is notable because it sees a time in history when nations will decide against war. Not as a temporary tactic. But as a permanent and thorough going strategy for relations with other nations.
The history of humanity suggests such a strategy would be foolish at best... and should be considered completely irresponsible.
The only thing that makes this non-violent strategy a realistic option is that all the nations of the world have come to learn of the ways of God. This represents an ultimate human phase - not of evolution - but of transformation (conversion).
When Jesus came to save the world, part of that saving is from the instinctual behavior we tend to react with. We are saved to share the love of God. To be transformed to the nature of God.