"He made no distinction between us and them."
In yesterday's first reading for Mass, from the Book of Acts, we are told by St. Peter (who was a Jew speaking mostly to other Jews), that God did not make a difference between the Jews and the Gentiles when He granted grace and forgiveness. As a Jew, this was a new thing to him, because they were used to being told by the Pharisees, the Sadducees and the Scribes that there was a difference and that the Gentiles were not as worthy as the Jews.
I have never heard anyone doubt this assessment; whether Catholic or protestant, whether Christian or pagan, everyone acknowledges that this is the true understanding that is presented to us in the Scriptures. What, however, if we switch the terms? Imagine for a moment that it is the Gentiles who are saying that God has not made a difference between them and the Jews. Would that make the theology different? No.
Let us, however, go one step further. Move everything up to the current day. What if someone were to say that he is "pro-Israel" because the Jews were special in God's sight? Would that fit with the clear declaration that God "made no distinction between" Jews and Gentiles? I do not mean that no one can "like" the nation of Israel (there is not much to like about the nation, but that is their choice). Nor am I myself, or do I want to encourage anyone else to be, "antisemitic".
Yet, if we are to take a position, politically, economically, theologically, or anything else, that says that one nation is always correct, and must always be agreed with, then there is a problem with that (many places in Scripture tell us that is wrong). Furthermore, if Scripture tells us specifically that God does not consider the "Jews" any different than the "Gentiles" at all any more, then we must agree with that. It would be just as wrong for someone to be, always "for the nation of Israel" as it would be to be always "for the nation of Uruguay" or "Svalbard".
I do not think there is anything wrong with someone being "pro-Israel". As long as it is not assumed that everyone else must be so. You can be "pro-New Zealand" or "pro-Japan", but it is not a biblical requirement. It is wrong for us as Catholics to claim that the approval and full acceptance of any nation is a necessary position for someone to hold in order to be considered a faithful Catholic.