But, he added, Israel could not accept everyone who wanted to come. Israel's Law of Return, which lies at the core of the state's very existence, says that anyone with a Jewish grandparent can settle in the Jewish state. But halachic, or religious, law specifies that a person can be Jewish only if he or she has a Jewish mother. To complicate the issue still further, there are bitter disputes between rabbinical authorities about the conversion of gentiles. Some orthodox Jews believe that conversion is impossible.
Liberal opinion holds it to be perfectly permissible.
Underlying the arcane debates about Jewishness is an uncomfortable if rarely voiced suspicion that Israel is holding the Falash Mura at arm's length because they are poor - and black.