A look at the troubled relations between Saudi Arabia, Iran

By executing a senior Shiite cleric, Saudi Arabia effectively lit a match to set off regional sectarian tensions and its rivalry with Iran, threatening to derail already-shaky peace efforts over the wars in Syria and Yemen.

Updated: January 5, 2016 8:39 am

Iran and Saudi Arabia have had tense diplomatic relations since the 1979 Islamic Revolution that overthrew Iranian Shah Mohammad Reza Pahlavi, although there have been occasional thaws.

Here’s a look at how ties between the Middle East rivals have shifted.

PRE-REVOLUTION

Iran had rocky relations with Saudi Arabia under the shah, but they improved toward the end of his reign in 1979. Both were original members of the oil cartel OPEC.

In this Nov. 3, 1973 file photo, a subcommittee of six Organization of Petroleum Exporting Countries (OPEC) meet to study the prices of oil, in Kuwait. The meeting comprises of Oil Ministers from Kuwait, Saudi Arabia, Iraq, Iran, Abu Dhabi and Qatar. AP Photo/File In this Nov. 3, 1973 file photo, a subcommittee of six Organization of Petroleum Exporting Countries (OPEC) meet to study the prices of oil, in Kuwait. The meeting comprises of Oil Ministers from Kuwait, Saudi Arabia, Iraq, Iran, Abu Dhabi and Qatar. (AP Photo/File)

POST-REVOLUTION

After the revolution and takeover of the U.S. Embassy in Tehran, Saudi Arabia became Washington’s top ally in the region. In the ensuing war between Iran and Iraq in the 1980s that killed 1 million people, Saudi Arabia backed Iraq despite concerns about dictator Saddam Hussein.

In this March 10, 1984 file photo, Iranian troops advance despite obstacles set by Iraqi forces in the Manjnoon Islands, Iraq. Smoke in background rises from Iraqi armored units set afire by Iranian forces. (AP Photo/File) In this March 10, 1984 file photo, Iranian troops advance despite obstacles set by Iraqi forces in the Manjnoon Islands, Iraq. Smoke in background rises from Iraqi armored units set afire by Iranian forces. (AP Photo/File)

1987 HAJJ RIOTS

The annual hajj pilgrimage to Islamic holy sites in Saudi Arabia, required of all able-bodied Muslims once in their life, saw bloodshed in 1987 when Iranians held a political demonstration. Iranian pilgrims later clashed with Saudi riot police, and at least 402 people were killed. Iran said 600 of its pilgrims were killed after police opened fire at the crowd. In Tehran, mobs attacked the Saudi, Kuwaiti, French and Iraqi embassies.

 

In this Aug. 18, 1955 file photo, King Saud of Saudi Arabia and his host, the Shah of Iran, travel by jeep on the way to view Iranian army maneuvers. King Saud was paying a state visit to his Persian Gulf neighbor. Diplomatic relations between Iran and Saudi Arabia have been tense since the 1979 Islamic Revolution, though there have been occasional thaws between the two rivals.(AP Photo, File) In this Aug. 18, 1955 file photo, King Saud of Saudi Arabia and his host, the Shah of Iran, travel by jeep on the way to view Iranian army maneuvers. King Saud was paying a state visit to his Persian Gulf neighbor. (AP Photo/File)

SEVERING TIES

Saudi Arabia cut ties with Iran in 1988, citing the hajj riots of a year earlier and Iran’s attacks on shipping in the Persian Gulf. The countries restored diplomatic ties in 1991.

In this undated 1979 file photo, Iran's new leader, Ayatollah Khomeini waves at the crowd at Qom, Iran. After the overthrow of the shah and takeover of the U.S. Embassy in Tehran, Saudi Arabia quickly became America's top ally in the region.(AP Photo, File) In this undated 1979 file photo, Iran’s new leader, Ayatollah Khomeini waves at the crowd at Qom, Iran. After the overthrow of the shah and takeover of the US Embassy in Tehran, Saudi Arabia quickly became America’s top ally in the region.(AP Photo, File)

EASING TENSIONS

Relations improved after Iranian President Mohammad Khatami, a political moderate, took office in 1997. They warmed further after historic visits by Saudi Crown Prince Abdullah to Tehran that year and Khatami to the kingdom in 1999.

In this Dec. 8, 1997 file photo, Saudi Arabia Crown Prince Abdullah Bin Abdul Aziz Al-Saud, center left, is greeted at Mehrabad Airport in Tehran by Iranian President Mohammad Khatami, center right, ahead of the Islamic Conference in the Iranian capital. (AP Photo/File) In this Dec. 8, 1997 file photo, Saudi Arabia Crown Prince Abdullah Bin Abdul Aziz Al-Saud, center left, is greeted at Mehrabad Airport in Tehran by Iranian President Mohammad Khatami, center right, ahead of the Islamic Conference in the Iranian capital. (AP Photo/File)

NUCLEAR DISPUTE

Saudi worries about Iran resumed amid international sanctions against Tehran over its contested nuclear program and the increasingly harsh rhetoric of Iranian President Mahmoud Ahmadinejad. Iran and Saudi Arabia each backed opposite sides in Syria’s civil war and the conflict in Yemen. Saudi Arabia also grew increasingly suspicious of Iran over the nuclear deal reached with world powers.

In this Oct. 3, 2015 file photo, Iranian officials pray as they touch the coffin of a dead hajj pilgrim who was killed in a deadly stampede in Mina near Mecca in Saudi Arabia, at Mehrabad airport in Tehran, Iran. In this Oct. 3, 2015 file photo, Iranian officials pray as they touch the coffin of a dead hajj pilgrim who was killed in a deadly stampede in Mina near Mecca in Saudi Arabia, at Mehrabad airport in Tehran, Iran. (AP Photo/File)

2015 HAJJ DISASTER

After a Sept. 24 stampede and crush struck the hajj, Saudi Arabia said 769 pilgrims were killed. An Associated Press count from other countries showed that over 2,400 people were killed. Iran said at least 464 of its pilgrims were killed and blamed Saudi “incompetence” for the deaths.

An Iranian woman holds up a poster showing Sheikh Nimr al-Nimr, a prominent opposition Saudi Shiite cleric who was executed last week by Saudi Arabia, in Tehran, Iran. (AP Photo/File) An Iranian woman holds up a poster showing Sheikh Nimr al-Nimr, a prominent opposition Saudi Shiite cleric who was executed last week by Saudi Arabia, in Tehran, Iran. (AP Photo/File)

SHEIKH’S EXECUTION

On Jan. 2, Saudi Arabia executed 47 people — including Shiite cleric Sheikh Nimr al-Nimr, a central figure in Arab Spring-inspired protests by Saudi Arabia’s Shiite minority. His death sparked protests across the Middle East and attacks on Saudi diplomatic facilities in Iran. Saudi Arabia responded by announcing it was severing diplomatic ties with Iran.