Tensions may deal a blow to the fight against terrorism

Saudi Arabia severed diplomatic ties with Iran on Sunday and asked all Iranian diplomats to leave the country within 48 hours after angry Iranian protesters stormed the Saudi embassy in Teheran in protest against the execution of 47 people, including prominent Shiite cleric Nimr al-Nimr, on terrorism charges by Riyadh. Following Saudi Arabia's move, Sudan and Bahrain severed ties with Iran and the United Arab Emirates said it would downgrade ties with Teheran.

The United Nations, the United States and the European Union all condemned the latest executions carried out by Saudi Arabia, and urged countries in the Middle East not to escalate religious tensions further. On the other hand, Iran's supreme leader Ayatollah Ali Khamenei said Saudi Arabia would face "divine revenge" for "unjustly spilling the blood" of Nimr and urged the Islamic world to strongly protest his death.

This is not the first confrontation between Riyadh and Teheran, which for decades have been fighting for the religious leadership in the Middle East. Portraying itself as the de facto leader of the Islamic world, the Sunni Saudi Arabia has prided its guardianship of the holy cities of Mecca and Medina, on which millions of Muslims converge to perform hajj every year. And Iran, as the largest Shiite Muslim country, has become a major security concern for many Gulf states, including Saudi Arabia, for not only following a different strand of Islam but also its growing military might.