The burden that Isaiah prophesied against Syria is cited in chapter 17 and goes along with the historical events of chapter 7. The Northern Kingdom of Israel (often called Ephraim) had joined arms with Syria to form a coalition in an attempt to stop the Assyrians from conquering them, yet it was to no avail, for the Lord had purposed to defeat Syria and chastise Israel. Isaiah's prophecy was fulfilled in 732 B.C., when Tiglath-pileser of Assyria destroyed Damascus, the capital of Syria (17:1). This lead to the defeat of the whole coalition army, for "the fortress" in Ephraim (Samaria, the capital city of the Northern Kingdom of Israel) would likewise be left in ruins by the Assyrians (17:3). He also predicted the scarcity of inhabitants in Israel (17:5-6), for the majority of people would be taken captive (under Sargon in 722 B.C.). Everyone who sees the sudden destruction will know it was the judgment of God upon them for forsaking Him, "the Rock" of their salvation and stronghold (17:10-11). The tragedy will cause them to look to their Maker and repent (2 Chron. 30:11; 34:9). They will learn to fear the Lord and no longer respect their idols (17:7-8), for such man-made images cannot give any help in times of need; only the "Rock" can provide true refuge.
After the Assyrians defeated Samaria, they continued south to Judah like a rushing torrent and plundered the many villages. Their seige on Jerusalem, however, was not successful, as Isaiah had previously prophesied (10:24-26). Here we have an event graphically described which Isaiah would live to see: the destruction of the Assyrians who would dare to plunder the people of the Lord. In the night, trouble would come for the Assyrian army, for the Lord would intervene, and before morning they would be no more (17:14; cf. 2 Kings 19:35; 2 Chron. 32:20-22).
Chapter 18 tells of God's judgment upon Ethiopia, a land which Isaiah describes as "shadowed with buzzing wings" (18:1), probably referring to the frequent locusts that sweep across Ethiopia and other parts of Africa. Isaiah prophesied that the Ethiopian nation would be in their prime and growing stronger when suddenly they would be cut down and preyed upon, like crops which are not yet ripe (18:5-6). The Assyrians did exactly that in their campaign of conquest. Isaiah ends his prophecy concerning Ethiopia with a glimmer of hope. They will not be totally destroyed, for they will live to pay tribute to the God of Israel by bringing a present to Jerusalem. This is possibly referring to the time when gifts from many nations, no doubt including Ethiopia, were brought to Hezekiah after the Lord had saved him and all Jerusalem from the Assyrians (2 Chron. 32:22-23). Another possible explanation is that many Ethiopians would become God-fearers (Gentile worshippers of the true God; 45:14; Ps. 68:31; 87:4; Zeph. 3:10), and make pilgrimages to worship God at His House at Jerusalem, as did the Ethiopian eunuch whom Philip led to the Lord (cf. Acts. 8:26-40).
The judgment of God upon Egypt is recorded in chapter 19. Isaiah prophesied these judgments on all these nations and it was "a sign" to show the people of Judah that it is futile to put their trust in them for deliverance from the Assyrians; the Lord is the only One upon whom they must rely (20:5-6). Egypt was once the strongest and most civilized nation in the world, yet Isaiah predicted that Egypt would suffer and become weakened by war with neighbouring nations (Ethiopia), as well as a civil war. Their military and economy would collapse due to the Lord's causing confusion so that the wise men of Egypt (who prided themselves in their wisdom) would give only foolish counsel (19:3, 14-15). Egypt would be extremely fearful and even paranoid of little Judah who, at that time, was weakened by Assyria (19:16-17; 2 Chron. 33:11). To make matters worse for Egypt, Isaiah prophesied a severe drought and since the livelihood of Egypt depended upon the Nile, everyone of every class would suffer (19:5-10). All these factors would enable the Assyrians to easily conquer Egypt (which they did in 671 B.C.). Isaiah prophesied that a fierce king would rule over them with much cruelty (19:4) and chapter twenty tells of Isaiah becoming a living illustration to dramatically portray the cruel way the Assyrians would lead away the Egyptian captives.
Because of the Assyrian oppression and the later Babylonian oppression, many people of Judah immigrated to Egypt for refuge and established their own Hebrew-speaking villages. The "language of Canaan", however, may refer to a population of people who will worship the Lord and speak only words of righteousness, purity, love, and truth (Zeph. 3:9, 13).
Isaiah explains that God will purpose all these tragedies to chastise Egypt and cause her to see her foolishness in consulting idols and charmers, so that they might call out to Him and God could heal them (19:22) and bring them unto Himself. The Lord had purposed that these Gentiles would come to know the God of Israel as their own, for they too will become His people if they have been saved by the "Saviour" and "Mighty One" whom God will send to deliver their souls from destruction and death (19:20-21). The Saviour will bring peace to the warring region and the three warring nations will become as one. Only during the righteous and peaceful reign of Jesus Christ will this be possible, for in Christ there is neither Jew nor Gentile and all those who follow Him He calls "My people" (19:23-25; cf. Gal. 3:26-29; Eph. 2:11-19; 1 Pet. 2:9-10).