Isaiah is a Millenialist. He often prophesies of the great and peaceful state of affairs during the Millenium. After the Lord comes to slay the wicked and fight Israel’s battles, peace will be established on the earth. There will be no more war for 1000 years, ’neither shall they learn war anymore.’ This is in great contrast to the wars which will directly precede the Second Coming. During this time period, as the prophet Joel explains, the people will be doing just the opposite—beating their plow-shares into swords in preparation for the ensuing battle, ’Prepare war, wake up the mighty men, let all the men of war draw near; let them come up: Beat your plowshares into swords, and your pruninghooks into spears: let the weak say, I am strong’ (Joel 3:9-10).
One of the tragedies of war, other than the loss of life, is the remarkable waste of resources. We might ask, “what if we took all the money used to make swords and used it to make plowshares instead?”
"Every gun made, every warship launched, every rocket fired signifies, in the final sense, a theft from those who hunger and are not fed, those who are cold and are not clothed.
"This world in arms is not spending money alone: It is spending the seat of its laborers, the genius of its scientists, the hopes of its children…This is not a way of life at all, in any true sense. Under the cloud of threatening war, it is humanity hanging from a cross of iron. (Dwight D. Eisenhower, Peace With Justice: Selected Addresses of Dwight D. Eisenhower [New York: Columbia University Press, 1961],37-38)
“Give me the money that has been spent on war,and I will clother every man, woman, and child in an attire of which kings and queens would be proud. I will build a schoolhouse in every valley over the whole earth. I will crown every hillseide with a place of worship, consecrated to the gospel of peace.” (Charles Sumner, as quoted by Gordon B. Hinckley, Ensign, Mar. 1971, 20)" (K. Douglas Bassett, Commentaries on Isaiah in the Book of Mormon, [American Fork, UT: Covenant Publishing Co., 2003], 37)
"Many take comfort from the Old Testament prophecy that nations will ’beat their swords into plowshares, and their spears into pruninghooks.’ (Micah 4:3.) But this prophecy only applies to that time of peace which follows the time when the God of Jacob ’will teach us of his ways, and we will walk in his paths.’ (Micah 4:2.)
“For now, we have wars and conflicts, and everywhere they are rooted in violations of the commandments of God.” (“World Peace,” Ensign, May 1990, 72)