Most of Greek Philosophy came after the Persian Wars, and it can be quite easily shown that much of Islam is, fundamentaly, based on, or heavily influenced by, Classical Greek Philosophy. Thus if Greece no longer exists in a manner that will allow the philosphers to prosper, Islam as we know it no longer exists. To quote Tom Holland in his book Persian Fire where he talks about how the Battle of Marathon and the Persian Wars were the origin of the concept of a battle between East and West (and how it continues today with the war on Terror): Had the Athenians lost the Battle of Marathon, and suffered the obliteration of their city... there would be no Plato-and Without Plato and the collosal shadow he cast on all subsequent theologies, it is unlikely that there would have been an Islam to inspire bin Laden. Later we have this quote: Although the defeat of Xerxes was certainly decisive in giving the Greeks, and therefore all Europeans, their own distincitiveness, the effect of the Persian Wars cannot be rigidly confined within the notions of East and West. Monotheism and the notion of a universal state, democracy and totalitarianism can all thrace their origins to this time.
We've also lost the Parthenon, and will see the gradual extiction of the classical orders.
