Paul is referring to the nation of Israel, God's elect nation. The were chosen by God to bring forth the Messiah. They are enemies of the gospel. Paul has a deep desire to see them saved.
The earthly nation of Israel is not God's elect nation. God divorced them in the Old Testament due to their spiritual fornication. Their
special place with God ended then:
[Jer 3:8 KJV] 8 And I saw, when for all the causes whereby backsliding Israel committed adultery I had put her away, and given her a bill of divorce; yet her treacherous sister Judah feared not, but went and played the harlot also.
[Jer 3:9 KJV] 9 And it came to pass through the lightness of her whoredom, that she defiled the land, and committed adultery with stones and with stocks.