Actually its through their fall Rom 11:11
Romans 11:11
I say then, Have they stumbled that they should fall? God forbid: but rather through their fall salvation is come unto the Gentiles, for to provoke them to jealousy.
You're reading that wrong.
He is saying that God is not through with unbelieving Israel.
That it only looks as if He is through with unbelieving Israel.
Later in the chapter he will again assert that God is able to graft them back in again.
What Paul is asserting is that God is in fact using His salvation of Gentiles during unbelieving Israel's fall, to provoke unbelieving Israel to jealousy through said Gentile salvation.
The passage does not stand alone. It is based on Romans 1-3 and 9-11.
So, there is all that to consider.
Not to mention, translation issues.
I prefer studying from a KJV, but ever aware its English is not only an earlier form of English, but a British one - both the word structure and words meanings of which at times differ from North American English.
As in the word "prevent" in following passage...
1 Thessalonians 4:15 For this we say unto you by the word of the Lord, that we which are alive and remain unto the coming of the Lord shall not prevent them which are asleep.
1 Thessalonians 4:16 For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God: and the dead in Christ shall rise first: 4:17 Then we which are alive and remain shall be caught up together with them in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord.
In our North American English, the word "prevent" is meant in the sense of "to keep from, or not allow."
Whereas in the Early Modern (British) English (of 500 years ago) it means "to precede, or go first."
Thus, a rule like "well it means what it says" will only fall short of what else is needed - other rules.
Like the rule of "comparing verse with verse."
As in comparing verse 15's "we which are alive and remain unto the coming of the Lord shall not prevent them which are asleep" with verse 16's "and the dead in Christ shall rise first:"
And then there is the issue of word structure. Again, all the above applies.
Thus why Rom. 11:11 only appears to be saying that "through their fall salvation is come unto the Gentiles."
In reality, Paul is asserting that one aspect of the salvation of God that He is now working among the Gentiles during unbelieving Israel's fall, has in mind His provoking unbelieving Israel to jealousy through said Gentile salvation.
Out the window goes your (Calvin's) doctrine of election, by the way.
Paul is talking about unbelieving Israel.