Saudi Arabia

King Salman's first year on the throne has brought big changes to the kingdom. It has a more aggressive foreign policy, is actively confronting Iran and is speaking out more openly than in the past.

As tension boils between the two regional powers, witnesses say it's not clear that Iran's embassy sustained damage, or was even hit.

The bitter rivalry may be more bad news for the long-suffering people of Syria. Also, Iran's President Hassan Rouhani has come off looking ineffectual.

Kuwait also summoned Iran's ambassador Tuesday to give him a note of protest over the failure to protect Saudi Arabia's diplomatic missions.

The kingdom's execution of Sheikh Nimr al-Nimr, who was highly critical of the Saudi government, marks a turning point in Saudi-Iranian relations and has sent shock waves through the region.

Announcing the move Monday, Bahrain said it is responding to "sinful cowardly attacks" on Saudi Arabia's embassy and a consulate in Iran.

The Saudi-Iran rivalry has been a fundamental fault line in the Middle East for decades and complicates most every major issue in the region, from the Syrian civil war to global oil markets.

A cold war in the Middle East just turned a lot hotter. Saudi Arabia, a Sunni power, and Iran, a Shiite one, have long been bitter rivals, but always maintained diplomatic relations — until now.