I firmly believe he has a right to free speech as the article does not suggest he is simply being a racist or something other as his critics accuse him of. He did not say "jews go to hell" or any of that but rather calmly constructed his argument and provided his reasons. Whether you agree with him or not, he should have a fundamental right to voice his perspective in a civilized world.
Jordan foreign minister says to speak with Kerry on Israel-Palestinian conflict (Reuters)
from the article: The Gospel according to Sand: We are not Jews