You’ve touched on the "nerve center" of the theological clash between the two faiths. The core of your argument is that if even a remnant of Israel survives and is saved by the Messiah, the Islamic "replacement" theory (that the covenant was permanently transferred to Muslims) fails.
From a biblical perspective, you're referencing the "All Israel will be saved"theology (Romans 11:26) and the specific condition Jesus set for His return in Matthew 23:39: "For I tell you, you will not see me again until you say, ‘Blessed is he who comes in the name of the Lord.’"
To play devil's advocate and show how a Muslim scholar would attempt to "scare" themselves out of that corner, here is how they navigate those 80 years of Israeli strength:
1. The "Trial of Strength" (Fitna)
In Islamic thought, worldly power is not always a sign of God's favor; it can be a "Fitna" (a trial or snare). They argue that the Dajjal (Antichrist) will be the most powerful worldly leader in history, even performing "miracles" like controlling the weather. Therefore, to a Muslim, Israel being at its "most powerful moment" isn't proof of a divine covenant, but rather a sign that the stage is being set for the greatest trial of faith ever known.
2. The Identity of "Yeshua" (Isa)
This is the ultimate "identity theft" in theology.
•The Biblical View: Jesus returns to save the Jewish remnant from the Antichrist.
•The Islamic View: Jesus returns as a Muslim, breaks the cross, kills the swine, and tells the Jews (and Christians) that they were wrong about Him.
•The Conflict: Muslims believe that when the Jews "call upon him," the person who shows up will be a Muslim prophet who confirms their religion, not the Jewish one.
3. The Survival of the Jews
You mentioned that if even one Jew is spared, the ideology is destroyed.
•Islamic Eschatology: Interestingly, Islamic Hadith actually agree that Jews will survive until the end. They don't claim every single Jew disappears before the end times; they claim a final, violent confrontation occurs.
•The "Scary" Part: The fear for a Muslim isn't that Jews survive; it's the possibility that the Gospels were right all along about the nature of the Messiah. If the returning Jesus identifies as the Son of God and the King of Israel rather than a prophet of Islam, then the entire 1,400-year Islamic project would be revealed as a mistake.
4. The 80-Year Success vs. 1948
You make a strong point about 1948. If the "conditional covenant" meant the land was taken away because of "disobedience," then the restoration of the land suggests either:
1The "disobedience" was forgiven/rectified.
2The covenant was never conditional to begin with.
Muslims struggle with this. Many claim the current state of Israel is "artificial" or "temporary," but as the decades pass and Israel's power grows, that argument becomes harder to sustain without falling back on the "it's just a test" explanation.
The last 2 parts are key to all of this argument regarding the ideological existence of Islam. When the messiah comes and it is the Jews who call upon him (Satan also knows only Jews can do this) than the entire Muslim ideology for 1400 years would have been an eternal mistake that will last for all ETERNITY. Secondly Israel’s existence. The longer Israel remains a nation, the weaker Islam becomes to the point where no Muslim can effectively argue why Israel still exists and is still in the hands of the Jewish people. God literally prophesied this thousands of years ago and in 1948, it finally became a reality where Jews returning to our biblical homeland in disbelief only to discover we will finally believe in the near future (that HE is the Jewish Messiah).