The LORD let the Israelis prosper and take over. They soon lost their identity as Israelites, but God knows who the descendants of Abraham are. He is keeping all of His promises to Abraham. He would be the father of many nations. The Israelite genes are mingled in all over the world, but in particular in Europe.
When Jesus comes back he will gather the members of the tribes of Israel who are left on earth after the great tribulation, and bring them back to Zion with rejoicing. The Jews already there will be shocked to find out that many of the people of the world who they considered gentiles are actually Israelites. The most surprised will be the Israelites themselves, who find out that they are actually Abraham's descendants.
Much of the Bible is around two subjects which, number one is the story of Christ, and number two the story of God keeping His promise to Abraham and causing his descendants to prosper and be ultimately blessed, and inherit the land of Israel.
Many “gentiles” are of the tribes because God has kept them, unbeknownst to themselves. Their fathers are a long line that trace all the way back to their tribal identity. Others are children of Abraham because somewhere back in their line their father/s or mother/s were Israelites, but though they are children of Abraham, they are not officially Israelites because Israeli identity is usually past through the father. God knows all, and knows the genetic pedigree of every person on earth and has also preserved His chosen Israeli line.
If many of the people who hate the Jews knew that they also have an Israeli genetic background, they might change their minds a bit.