The Israeli Interior Ministry has determined that the small Ugandan community of Jews called Abayudaya are not Jewish enough to be eligible to immigrate to Israel.
They converted to Judaism in early the 1900s, doing so with no contact with established communities in the Diaspora, which I think is pretty amazing.
I suppose this decision is probably because the Abayudaya are associated with Conservative Judaism, through which formal conversions occurred in relatively recent history.
Surely supporting these nascent communities can only benefit Israel? How about just the simple fact that there is strength in numbers?