The expansion of Israel's borders
In Genesis 15, God revealed to Abraham the boundaries of the future nation of Israel.
“On that day the Lord made a covenant with Abram and said, “To your descendants, I give this land, from the Wadi of Egypt to the great river, the Euphrates— the land of the Kenites, Kenizzites, Kadmonites, Hittites, Perizzites, Rephaites, Amorites, Canaanites, Girgashites, and Jebusites.” (Genesis 15:18-21)
The boundaries noted by God in Genesis 15 were affirmed to Isaac in Genesis 26, declared to Jacob in Genesis 28, and confirmed by Moses in Exodus 23:31. The Promised Land began to be possessed in the days of Joshua, it became a strong and unified nation in the Days of David, and its borders were expanded in the days of Solomon. However, the borders of Israel have never matched the vast footprint God noted in Genesis 15.
Some suggest that the borders of Israel will not expand much beyond post-1967 war borders until the Millennial Kingdom (which will come after the Tribulation period). However, a number of prophecies suggest that borders could expand as a result of war or military engagements—something that is not expected to be a part of the Millennial Reign of Christ. Those who believe Israel's borders will expand as a result of the Psalm 83 or Isaiah 17 conflicts, believe that expanded borders will contribute to the sense of security the prophecy of Ezekiel 38:10 notes Israel will enjoy prior to the Gog-Magog invasion (which precedes the Battle of Armageddon and the Millennial Kingdom). The two probable scenarios for pre-millennial border expansion are 1) borders will be expanded as a result of Israel’s response to the attack profiled in Psalm 83 2) borders will be expanded in the subsequent battles which will include the destruction of Damascus (Isa. 17) and a devastating strike on an important military site on Elam (Iran, Jer. 49).
PASSAGES NOTING THE EXPANSION OF ISRAEL’S BORDERS
Saudi Arabia: “…I will stretch out my hand against Edom…I will lay it waste, and from Teman to Dedan (Saudi Arabia) they will fall by the sword. I will take vengeance on Edom by the hand of my people Israel…they will know my vengeance, declares the Sovereign LORD.” (Ezek. 23:13-14)
Jordan: “The days are coming, “declares the LORD, "when I will sound the battle cry against the Ammonites (Jordan); it will become a mound of ruins, and surrounding villages will be set on fire. Then Israel will drive out those who drove her out," says the LORD.” (Jer. 49:2)
The region of Saudi Arabia and Jordan: "Saudi Arabia and Jordan: Turn and flee, hide in deep caves, you who live in Dedan (Saudi Arabia), for I will bring disaster on Esau [Southern Jordan] …” (Jer. 49:8)
Egypt: “In that day the Egyptians…will shudder with fear at the uplifted hand that the LORD Almighty raises against them. And the land of Judah will bring terror to the Egyptians…” (Isaiah 19:16-17a)
Syria/Damascus: “Behold, Damascus is about to be removed from being a city…The cities of Aroer will be deserted…The fortified city will disappear…the land will be a desolation…At evening time, behold, there is terror! Before morning they are no more.” (Isaiah 17:1-3)
Individuals will be displaced: "Like a lion (Psalm 83 confederacy) coming up from Jordan's thickets to a rich pastureland (Israel), I will chase Edom.” (Jer. 49:19)
Egypt: “The land of Judah will become a terror to Egypt…In that day five cities in the land of Egypt will be speaking the language of Canaan and swearing allegiance to the LORD of hosts; one will be called the City of Destruction. In that day there will be an altar to the LORD in the midst of the land of Egypt, and a pillar to the LORD near its border.” (Isaiah 19:17-19)
The Arab world will be enraged: "Oh, the raging of many nations— they rage like the raging sea! Oh, the uproar of the peoples—they roar like the roaring of great waters!” (Isa. 17:12)
Conclusions
God has a plan, and His plan is perfect. God reveals His plan in the way and time He determines best.
Many of the prophecies can be fulfilled rapidly, or simultaneously. World events can change quickly—current alliances are subject to change—former friends can become fierce enemies overnight. It is not wise to have strong opinions regarding it taking months or years for change to take place or prophecies to unfold.