It is my hope that the author did not make the mistake of confining the salvation of “all Israel” to a singular ambiguous event in the future. I have not read the book myself, although I believe I can explain what the author might have been trying to get across. The pope left the allusion to the salvation of Israel in Romans 11:25-27 (Motu proprio Summorum Pontificum, of July 7, 2007) as general as the Catholic Catechism leaves it in Paragraph 674:
vatican.va/archive/ENG0015/__P1V.HTM
674 The glorious Messiah’s coming is suspended at every moment of history until his recognition by “all Israel”, for “a hardening has come upon part of Israel” in their “unbelief” toward Jesus.568 St. Peter says to the Jews of Jerusalem after Pentecost: "Repent therefore, and turn again, that your sins may be blotted out, that times of refreshing may come from the presence of the Lord, and that he may send the Christ appointed for you, Jesus, whom heaven must receive until the time for establishing all that God spoke by the mouth of his holy prophets from of old."569 St. Paul echoes him: "For if their rejection means the reconciliation of the world, what will their acceptance mean but life from the dead?"570 The “full inclusion” of the Jews in the Messiah’s salvation, in the wake of “the full number of the Gentiles”,571 will enable the People of God to achieve “the measure of the stature of the fullness of Christ”, in which “God may be all in all”.572
Both the Latin Mass Prayer for the Jews and the Catholic Catechism leave open the interpretation that “all Israel shall be saved” and does not refer exclusively to an event in the future in which masses of Jews will be saved, but to the fact that “Israel,” the Jews, have been coming into the Church since ancient times, while at the same time, “the fullness of the Gentiles,” by the influx of various individuals from the nations into the Catholic Church, has also been occurring. In this way, the “fullness of the Gentiles” and the saving of “all Israel” are presently occurring and both will reach their fruition at the Second Coming of Christ. All the Jews that become saved, from the time of Abraham to the return of Christ, comprise the “all Israel” that will be saved.
