Stephen Sackur speaks to Mohammed AlHussaini Al Sharif, a Saudi diplomat who is the Arab League envoy in Washington, asking if the new brand of muscular Saudi leadership in the Arab world is either credible or sensible. Powerful forces within the Arab World believe the time has come for Sunni Arabs to confront a perceived regional threat from Shiite Iran. That is a big factor in the Saudi-led bombardment of Shia rebels in Yemen - it also underpins the Arab League's plan to create a pan-Arab intervention force.