According to Paul in Romans 12, it was only through the first century restoration of Israel that the nations (Gentiles) had hope. Paul’s point was that since Jesus came and “made good” (confirmed) the promises made to the fathers, those promises (Isaiah 11) were being fulfilled, and the Gentiles were receiving of them also. Only through complete restoration of the remnant of Israel can the nations now “glorify God for his mercy”.
The Institute Of Fulfilled Eschatology