Incorrect, all fertile land must be inhabited for our world to expand at the rate that it is now. Otherwise, the human race would suffer even more limited expansion. Also, how would Israel being destroyed solve anything?
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If Iran destroys Israel, Iran is destroyed. So if you are calling for action, you do not understand politics.
Hypothetically, we will never know if the world would be better without Israel. The decision to move the Israeli's there in 1948 was very stupid, yet now they are living there and will fight their hardest for their place.