By Dr. Michael J. Vlach
I would like to offer a two-part entry on Isa 2:1-4, a passage that describes international peace among nations under the rule of Messiah in His kingdom. These conditions are not taking place in our present age but will when Jesus returns and sets up His kingdom.
Isaiah 2 addresses the coming kingdom and the roles of Israel and the nations in it. The message predicts international harmony among nations as a result of the Messiah's reign. The sons of Israel that God raised up "revolted" against Him (Isa 1:2). They were a "sinful nation" and "people weighed down with iniquity" (1:4). The once "faithful city" became a "harlot" and justice was not found in it (1:21). But a reversal of fortune will occur as "Zion will be redeemed with justice" (1:27). This is explained in Isa 2:1-4 where a glorious kingdom is presented and nations stream to Jerusalem to worship God. 
Isaiah says, "The word which Isaiah the son of Amoz saw concerning Judah and Jerusalem" (2:1). The Israelite connection here must not be missed. What is discussed in 2:2-4 concerns the geographical areas of "Judah and Jerusalem." Alexander is not correct when he states, "the Prophet sees the church, at some distant period, exalted and conspicuous, and the nations resorting to it for instruction in the true religion...."  This does not do justice to what Isaiah is saying and introduces a spiritualizing element that is not warranted from this passage or the New Testament. Isaiah is addressing international harmony that will occur among nations in the kingdom that has Jerusalem as the center of it. The kingdom truths of Isaiah 2:2-4 read:
Now it will come about that In the last days The mountain of the house of the LORD Will be established as the chief of the mountains, And will be raised above the hills; And all the nations will stream to it. And many peoples will come and say, "Come, let us go up to the mountain of the LORD, To the house of the God of Jacob; That He may teach us concerning His ways And that we may walk in His paths." For the law will go forth from Zion And the word of the LORD from Jerusalem. And He will judge between the nations, And will 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.
This section highlights four key elements:
- The preeminence of Mount Zion.
- Gentile pilgrimage to Mount Zion.
- The LORD judging the nations.
- The removal of weapons of warfare. 
All of this is in regard to "the last days," which in the Old Testament prophets refer to the days of Messiah and Israel's restoration. In the New Testament "last days" has significance for both the first and second comings of Jesus the Messiah.  Since what is described in Isaiah 2 has not occurred yet in regard to "Judah and Jerusalem" the fulfillment of this text awaits the second coming of Jesus.
The term "mountain" refers to Mount Zion in Jerusalem, the mountain on which God's temple sits. The "house of the LORD" is the temple. Mount Zion in Jerusalem will be exalted and elevated above the mountains and hills around it. In Isaiah's day, Mount Zion did not tower above other mountains but in the "last days" it will. But is this a reference to changes in Mount Zion's physical elevation or is this an elevation in the sense of prominence? We see no reason why both cannot be true. A physical entity can also convey a figurative meaning. Thus, Mount Zion can be elevated physically and in prominence. Zechariah 14:4-8 indicates that when Jesus returns to earth there will be massive geographic changes that affect the Mount of Olives, Jerusalem, and the land of Israel.
As Isaiah continues, this kingdom is centered in Israel, but it is not only for Israel. There is a universal element since "all the nations will stream to it" (2:2d) and "many peoples will come and say, 'Come, let us go up to the mountain of the LORD'" (2:3a). The rest of verse 3 indicates that the Gentile nations desire to go to the temple in Jerusalem to learn how to walk in God's paths and follow His law. Such positive statements concerning Gentile nations is striking since the nations of Assyria and Babylon are imminent threats to the nation Israel and Israel is not thinking fondly of the Gentile nations at this point. Nations are often the enemies of Israel. In fact, the era of the "times of the Gentiles" continues until this very day (see Luke 21:24). But during this kingdom era, the nations, as Grogan puts it, "come, not for plunder, but in peace, not to rob, but to learn." 
Diligent Jews often would make pilgrimages to the holy city as part of their worship. But in the last days, "what had been Israel's experience in the past would one day be that of all the nations."  There are also implications concerning the Exodus and Mount Sinai here. At the time of the Exodus the Hebrews went to Mount Sinai to receive God's law, but during this messianic era the nations are streaming to Mount Zion to learn God's law. 
Verse 4 details the LORD’s reign at this time. He will "judge between the nations" and "render decisions for many peoples." Several things are worthy of note here. First, literal geo-political nations exist in the days of the kingdom. And these nations are doing real activity. Second there are political judgments and decisions being made by the LORD for these nations. The word "judge" (shaphat) means to "govern, vindicate, or punish." According to Brown-Driver-Briggs the term here in Isa 2:4 concerns "decid[ing] controversy" in regard to "civil, political, domestic, and religious questions."  Thus, the LORD will make executive and judicial decisions in regard to the nations that are in need of righteous judgments. These nations, which appear to disagree at times or have conflicts of interests, will accept His announcements peacefully without taking matters into their own hands.
The need for settling disputes among nations points to an intermediate kingdom since these conditions do not fit the present age or the coming eternal state. As Saucy writes, "That sin is present during the Messiah's reign is evident in his settling disputes among the nations (cf. Isa 2:4).... "  This is not occurring today. But it will be in the latter days. This combination of conditions is found in Zechariah 14 where the LORD who is present on earth after His coming (see Zech 14:9) will bring "punishment" on nations who do not act as they should (Zech 14:18-19).
According to verse 4, universal peace will exist. The money and materials usually poured into military might and war will be devoted to peaceful pursuits. Swords will be hammered into plowshares and spears into pruning hooks showing that there is no longer a need for weapons of warfare. Whether there will be a literal transformation of swords and spears is a secondary issue. The main point is that weapons for warfare are no longer needed. When one considers how much money is poured into military purposes by countries today, it is staggering to think of the good that can be accomplished when valuable resources are no longer used for warfare. Such will be the case when the Lord is reigning upon the earth. Also, human ingenuity will no longer be used for weapons of destruction. As Bultema notes, "All military science, which today has reached such terrifying proportions, will then belong to a dark past." 
 The language here closely parallels that in Micah 4:1-3 highlighting the significance of this message.
 Joseph A. Alexander, Commentary on Isaiah (Grand Rapids: Kregel, 1992), 96.
 See Sailhamer, "Evidence from Isaiah 2," 85.
 Hebrews 1:2 indicates that "in these last days" God "has spoken to us in His Son." Yet the New Testament also speaks of many eschatological events that have not been fulfilled with the first coming of Jesus and await future fulfillment (see 1 Thess 4-5; 2 Thess 1-2; 2 Peter 3, etc.). The interpreter will need skill in deciphering which aspects of OT eschatology apply to Jesus' first coming and which apply to His second coming.
 G. W. Grogan, "Isaiah," in The Expositor's Bible Commentary, ed. Frank E. Gaebelein, vol. 6 (Grand Rapids: Zondervan, 1986), 35.
 Sailhamer, 90.
 I agree with Sailhamer that the nations are not under the Mosaic Law but the New Covenant law predicted for the latter days in Jeremiah 31 and Ezekiel 36. He says, "The translation 'law' in Isaiah 2:3 in the NASB rather than 'Law,' then, accurately reflects the emphasis of this passage away from the Sinai Law per se. The 'law' as used here in Isaiah is the internalized law of passages such as Jeremiah 31:33 and Ezekiel 36:27" (Sailhamer, 91).
 F. Brown, S. Driver, and C. Briggs, "fpv," The Brown-Driver-Briggs Hebrew and English Lexicon (Hendrickson, 1906, fifth printing 2000), 1047.
 This is Saucy's view, The Case for Progressive Dispensationalism, 234.
 Bultema, 56.