Why are Iran and Saudi Arabia so at odds?

CNN -

CNN—Iran and Saudi Arabia: Two regional superpowers going head-to-head across the Middle East. CNN's Becky Anderson explains the tense relationship between the two countries.

Israel and Saudi Arabia find common cause in keeping Iran at bay. A Swiss newspaper, Basler Zeitung, reported recently that a secret alliance between Israel and Saudi Arabia aimed at restraining Iran's imperial desire for a land mass between Tehran and the Mediterranean was moving into a new phase. While there aren't formal diplomatic ties between the two countries, military cooperation does ...