Saudi Arabia and Iran have sought to extend their influence in Bahrain for decades.
While the majority of Muslims in Bahrain are Shia, the country is ruled by the Sunni Al Khalifa family - who are widely viewed as being subservient to the Saudi government.
Iran claimed sovereignty over Bahrain until 1970, when Shah Mohammad Reza Pahlavi abandoned claims after negotiations with the United Kingdom.
The Iranian Revolution led to resumed interest in Bahraini affairs.
In 1981, the front organization Islamic Front for the Liberation of Bahrain led a failed coup attempt to install a Shia theocratic regime led by Hadi al-Modarresi.
Since then, the government has accused Iran of supporting terrorist plots within its borders.

Sunni states have long feared that Iran might stir up unrest among regional Shia minority populations, especially in Bahrain.
The Al Khalifa regime's stability depends heavily on Saudi support.
The island is connected to Saudi Arabia by the 25 kilometer King Fahd Causeway, and its proximity to Saudi Arabia's oil-rich, majority Shia Eastern Province is viewed by Riyadh as a security concern.
Any political gains by the Shia in Bahrain are seen by the Saudis as gains for Iran.

In response to the Arab Spring in 2011, the GCC regimes sought to maintain their legitimacy through social reform, economic handouts, and violent repression.
Member states also distributed a share of their combined oil wealth to Bahrain and Oman to maintain stability.
Saudi-led GCC forces quickly intervened in support of the Al Khalifa regime to put down the anti-government uprising in Bahrain.

The Bahraini government publicly blamed Iran for the protests, but an independent commission established by King Hamad rejected the claim, instead highlighting human rights abuses committed in the crackdown.
The protests, along with the Iran nuclear deal, strained Bahrain's relationship with the United States.
Bahrain has sought closer ties with Russia as a result, but this has been limited due to Saudi Arabia's alliance with the US.

Following the onset of the Arab Winter, Bahrain accused Iran of orchestrating several domestic incidents as part of a campaign to destabilize the country.
Tehran denied all allegations and accused the government of Bahrain of blaming its own internal problems on Iran after every incident.
In August 2015, authorities in Bahrain arrested five suspects over a bombing in Sitra.
Officials linked the attacks to the Revolutionary Guard and Hezbollah, although Iran denied any involvement.
In January 2016, Bahrain joined Saudi Arabia in cutting diplomatic ties with Tehran following the attacks on Saudi diplomatic missions in Iran.
In November 2017, Bahrain called an explosion on its main oil pipeline "terrorist sabotage" linked to Iran, drawing a rebuke from Tehran.
Saudi Arabia also referred to the incident as an "attack on the pipeline".
Saudi Arabia and Iran have sought to extend their influence in Bahrain for decades. While the majority of Muslims in Bahrain are Shia, the country is ruled by the Sunni Al Khalifa family - who are widely viewed as being subservient to the Saudi government. Iran claimed sovereignty over Bahrain until 1970, when Shah Mohammad Reza Pahlavi abandoned claims after negotiations with the United Kingdom. The Iranian Revolution led to resumed interest in Bahraini affairs. In 1981, the front organization Islamic Front for the Liberation of Bahrain led a failed coup attempt to install a Shia theocratic regime led by Hadi al-Modarresi. Since then, the government has accused Iran of supporting terrorist plots within its borders.
Sunni states have long feared that Iran might stir up unrest among regional Shia minority populations, especially in Bahrain. The Al Khalifa regime's stability depends heavily on Saudi support. The island is connected to Saudi Arabia by the 25 kilometer King Fahd Causeway, and its proximity to Saudi Arabia's oil-rich, majority Shia Eastern Province is viewed by Riyadh as a security concern. Any political gains by the Shia in Bahrain are seen by the Saudis as gains for Iran.
In response to the Arab Spring in 2011, the GCC regimes sought to maintain their legitimacy through social reform, economic handouts, and violent repression. Member states also distributed a share of their combined oil wealth to Bahrain and Oman to maintain stability. Saudi-led GCC forces quickly intervened in support of the Al Khalifa regime to put down the anti-government uprising in Bahrain.
The Bahraini government publicly blamed Iran for the protests, but an independent commission established by King Hamad rejected the claim, instead highlighting human rights abuses committed in the crackdown. The protests, along with the Iran nuclear deal, strained Bahrain's relationship with the United States. Bahrain has sought closer ties with Russia as a result, but this has been limited due to Saudi Arabia's alliance with the US.
Following the onset of the Arab Winter, Bahrain accused Iran of orchestrating several domestic incidents as part of a campaign to destabilize the country. Tehran denied all allegations and accused the government of Bahrain of blaming its own internal problems on Iran after every incident. In August 2015, authorities in Bahrain arrested five suspects over a bombing in Sitra. Officials linked the attacks to the Revolutionary Guard and Hezbollah, although Iran denied any involvement. In January 2016, Bahrain joined Saudi Arabia in cutting diplomatic ties with Tehran following the attacks on Saudi diplomatic missions in Iran. In November 2017, Bahrain called an explosion on its main oil pipeline "terrorist sabotage" linked to Iran, drawing a rebuke from Tehran. Saudi Arabia also referred to the incident as an "attack on the pipeline".
Iran–Saudi Arabia proxy conflict