“God has a covenant with Israel.” - Yes,and we have been grafted into it.
I suggest that you reread the whole chapter of Romans 11. Then go read the Abrahamic Covenant and the Davidic Covenant. Then come back to talk.
For now, please set aside the Law from Moses.
“In speaking of a new covenant he treats the first as obsolete. And what is becoming obsolete and growing old is ready to vanish away.” Hebrews 8:13
There are not two covenants, but one. “Drink of it, all of you; for this is the blood of the covenant, which is poured out for many for the forgiveness of sins.” Matt. 26:28-29
This, of course, was spoken to Jews. There is only one sacrifice, only one covenant, and only one Savior. And we have been grafted into it. Praise be to God!