AP Photo

With events still unfolding inside Iran, it is not yet clear how things will pan out for the Islamic Republic, which now faces its greatest challenge since the regime's early revolutionary days. But the reverberations of Iran's internal tumult since the June 12 presidential elections are potentially far-reaching: Iran's Arab neighbors, Israel, the European Union and, perhaps most importantly, the United States, are all observing developments closely to see how the crucial Middle East power's internal ructions might impact their own strategic interests.