Do you mean because of their birthrates relative to the surrounding Muslim populations who hate them? I proposed that idea on another thread a while back and got attacked as a Jewish shill, but I don't see how Israel isn't doomed due to low birth rates.
I don't see the state of Israel surviving. They are accruing more detractors and enemies; and are conveniently situated in a small area surrounded by bitter enemies. With the decline of The West, they will have no one to do their bidding or protect them.
On top of that, as you mention, there is the low birth-rates. Jews have the lowest birth-rate of any group wherever they live and they have high out-group marriage rates. They also seem to have large rates of drinking their own liberal kool aid. Many liberal Jews are moving towards open-border-type positions.