Saudi Arabia severed diplomatic ties with Iran on Sunday, as an escalating war of words between the two arch rivals threatened to derail a renewed international bid to halt the conflict in Syria.Riyadh gave Iranian diplomats 48 hours to leave Saudi Arabia after Iranian leaders condemned the execution of a popular Shiite cleric, Nimr Baqr al-Nimr, and after protesters stormed the Sunni kingdom's embassy in Tehran in anger over his death.The rupture between Saudi Arabia and Iran came at a delicate moment in the fledgling diplomatic effort to launch peace talks later this month between the Syrian regime of Bashar al-Assad and opposition representatives. Read more