Same place the rhodesians went. Many stayed in the new country (Zimbabwe), many immigrated away to surrounding countries or Europe. In the case of Israel a simikar situation can happen, and mang Israelis are dual citizens.
OK, and how to do propose this frankly deranged and unworkable plan is put into effect? A full scale invasion of Israel? By whom? What about the Israelis who don't have dual citizenship?
I'm asking for details from you and OP. All I'm getting is vague hand waving.
Give it back to Britain, or since it’s basically a US state elect someone willing to put the boot down. Those without dual citizenship cna become citizens of the new country / territory.