I do admire Rabbi Kahane's devotion to Israel and the Jewish people. He is probably the only member of the Knesset who reads world history as it was.
Since he admits that Western-style democracy has no place in a permanently Jewish state, then I can see, down the road, that Israel will be following the same sad and hopeless path of South Africa and Rhodesia. There is no democratic way to deny Israeli Arabs their voting rights and their population growth.
Another problem that can ruin Israel is its own socialist economics. Endless strikes, union demands, welfare, and inflation can also destroy a nation.