Last October, Saudi Arabia’s Special Criminal Court sentenced Sheikh Nimr Baqir al-Nimr  a popular Shi’ite cleric and outspoken political dissident  to death.

This was not an ordinary criminal trial, even considering Saudi Arabia’s liberal use of capital punishment. Among other charges, the prosecutor sought to convict al-Nimr of “waging war on God” and “aiding terrorists,” even calling for the cleric to be publicly executed by “crucifixion.” In Saudi Arabia, this rare method of execution entails beheading the individual before publicly displaying his decapitated body.

The widely revered Shi’ite cleric was ultimately convicted of “disobeying” the king, waging violence against the state, inviting “foreign meddling” in the kingdom, inciting vandalism and sectarian violence, and insulting the Prophet Muhammad’s relatives. However, al-Nimr’s family and supporters claim that the ruling was politically driven and insist that the cleric led a non-violent movement committed to promoting Shi’ite rights, women’s rights, and democratic reform in Saudi Arabia.

Since the October 15 ruling, high-ranking political and religious authorities in Iran and international human rights organizations have sought to pressure the Saudi Arabian leadership into sparing al-Nimr’s life. Demonstrations demanding that the death sentence be revoked have been held in Saudi Arabia, Bahrain, Yemen, and the United Kingdom, underscoring the international sensitivity surrounding al-Nimr’s imprisonment and death sentence.

While many experts doubt that the Saudi Arabian authorities will actually carry out the execution, it is important to take stock of the political context in which the Special Criminal Court issued the death sentence.

Saudi Arabia’s Restive Shi’ite Minority

Saudi Arabian Shi’ites have long complained of state-sponsored discrimination and human rights abuses by conservative Sunni authorities. According to Human Rights Watch, Saudi Arabian Shi’ites “face systematic discrimination in religion, education, justice, and employment.”

In early 2011, anti-government protests erupted in the Qatif district of Saudi Arabia’s Eastern Province, which is home to nearly all of Saudi Arabia’s 3 million Shi’ite citizens and nearly one-fifth of the world’s oil supply. Throughout 2011 and 2012, al-Nimr was a leader in these protests, in which activists demanded the release of the “forgotten prisoners”  a reference to nine political prisoners who had been detained then for some 16 years.

After Saudi Arabian, Emirati, and Kuwaiti forces entered Bahrain to help quell a non-violent Shi’ite uprising in the tiny island kingdom, Saudi Shi’ites expressed solidarity with their Bahraini counterparts. This prompted officials in Riyadh to fear that growing Shi’ite dissent could trigger a crisis in the strategically vital Eastern Province, which borders several other countries with sizeable Shi’ite populations. So between March 2011 and August 2012, the Saudi government waged a harsh crackdown on Shi’ite protestors, killing over 20, injuring several dozen, and detaining over 1,000 others, including 24 children.

Following the shooting of four Shi’ites in the Eastern Province in November 2011, al-Nimr spoke at one of their funerals. “We are determined to demand our legitimate rights by peaceful means,” he declared. Al-Nimr, who had already been detained several times by that point, had called for peaceful resistance to the ruling monarchy on numerous other occasions, despite Riyadh’s allegations that the cleric incited violence.

On July 8, 2012, Saudi security forces shot, wounded, and arrested al-Nimr after clashing with his bodyguards. Amnesty International condemned the arrest and described the cleric as “an outspoken critic of the policies and practices of the Saudi Arabian authorities affecting the [Shi’ite] community, including detentions without charge or trial, and excessive use of force against protestors.”

Al-Nimr’s trial began in March 2013. According to the Saudi Press Agency, the judges claimed that the cleric was “insistent” and “stubborn” during the trial. Al-Nimr did not deny the charges levied against him, yet he maintained that he never incited violence.

Daesh and Saudi Arabia’s Domestic Environment

Anti-Shi’ism has served as a pillar of the Wahhabi brand of Sunni Islam ever since Muhammad ibn Abd al-Wahhab founded the movement in the 18th century. By inciting violence against Shi’ites in the Arabian Peninsula and beyond, Saudi Arabia’s political leadership has maintained the alliance with the kingdom’s hardline Wahhabi religious establishment (which views all Shi’ites as “heretics” and holds notoriously intolerant views of Christians and Jews) that led to the formation of the modern-day state of Saudi Arabia in 1932.

However, the rise of Daesh (or the “Islamic State”) in Iraq and Syria  combined with the threat of violence from Daesh sympathizers inside Saudi Arabia  has put the government in an interesting position of having to defend its Shi’ite citizens from the rigidly anti-Shi’ite group.

Daesh’s capacity to increase Saudi Arabia’s sectarian temperature was demonstrated last November, when three Saudis and one Qatari linked to Daesh used machines guns and pistols to kill five Saudi Arabian Shi’ite worshippers in the Ahsa district of Dalwah. In contrast to the government’s traditional role of promoting anti-Shi’ite bigotry, Saudi authorities responded the following day by shutting down Wesal TV, which had broadcast programs that labeled Shi’ites as “rejectionists.” Later than month, Saudi Arabian security forces killed three of the four men responsible for the attack and uncovered a Daesh-linked cell comprised of 77 members (three came from Jordan, Syria, and Turkey; the rest were Saudi Arabian nationals) that stored the weapons used in the Dalwah attack.

The threat from Daesh and its sympathizers in the country poses a new security and ideological challenge for Riyadh, which previously faced an al-Qaeda insurgency from 2003-2006 that killed hundreds of Saudi Arabians. Yet the authorities’ response to this new menace has not been well received among certain conservative circles within the kingdom.

The official position of Saudi Arabia  a key Arab member of the U.S.-led military campaign against Daesh in Iraq and Syria  is that Daesh and the Damascus regime must be simultaneously defeated.

However, some Saudis are not sold. By taking military action against Daesh while not striking against Bashar al-Assad’s forces, they say, Saudi Arabia is aligning itself with Iran, Syria, and Lebanon’s Hezbollah. Some hardline Saudis believe that Daesh deserves Riyadh’s support for serving as a Sunni bulwark against Iranian-backed governments in Baghdad and Damascus. Even some Saudi Sunnis who are opposed to Daesh’s ideology and fearful of the group’s agenda object to the bombing of Sunni Arabs combating the Alawite-led regime in Syria.

Within this context, the Saudi Arabian government’s treatment of al-Nimr serves to communicate that while Riyadh channels greater resources toward the threat of Sunni extremism, the monarchy has not abandoned efforts to crush all forms of Shi’ite dissent in the restive Eastern Province. It is part of an effort by the government to prevent Daesh from exploiting a perception within hardline Wahhabi circles that Riyadh is becoming “soft” on Shi’ite activism at home and abroad.

A Shi’ite Backlash on Saudi Arabia’s borders

But that strategy comes at a cost. Al-Nimr’s prosecution and death sentence have triggered an outcry among Shi’ites across the Middle East, leaving little doubt that al-Nimr’s execution would worsen the violent state of sectarian unrest in the region.

Iran’s religious establishment in particular has harshly condemned al-Nimr’s sentence. Conservative Iranian ayatollahs  including Jafar Sobhani, Hossein Nuri-Hamadani, and Naser Makarem Shirazi  have warned Riyadh that al-Nimr’s execution would produce “unpredictable results” and that “such cruel actions will have consequences.” Iran’s Fars News Agency quoted Ayatollah Ahmad Khatemi, who admonished Saudi Arabia’s leadership that “the execution of this scholar of religion will result in tough and serious repercussions, and it will cost you dearly.”

Bahraini Shi’ites have held protests in solidarity with al-Nimr that resulted in clashes with local police. Militant Shi’ite factions in the island kingdom have also mobilized in response. Last August, Saraya al-Mukhtar  an organization that has pledged solidarity with its Shi’ite counterparts in Saudi Arabia  launched an assault near a Bahraini military base, citing al-Nimr’s imprisonment as the motivation.

The group also issued threats on Facebook against U.S. troops stationed in Bahrain, proclaiming that Washington’s support for the ruling Saudi Arabian and Bahraini monarchies makes the U.S. a legitimate target if al-Nimr is executed. On August 10, the group threatened Saudi nationals in Bahrain with a poster warning that “harming [al-Nimr] means every single Saudi national will enter our country in a coffin.”

The following October, the group claimed responsibility for attacks in Sanabis and Aker. “The occupying mafia of Al Saud and Al Khalifa,” it said in a statement referring to the Saudi and Bahraini monarchies, will “face consequences for the death sentence.” Three days later, the Shi’ite faction referred to the attacks as “revenge of the Faqih [a scholar in Islamic jurisprudence] Nimr” and claimed that the violence targeted the “ranks of the enemy occupier,” referring to Saudi Arabia.

Bahraini officials have painted over pictures of al-Nimr that Shi’ites had plastered on walls to demonstrate solidarity with the cleric. Unquestionably, officials in Manama must be concerned about security risks in Bahrain as well if al-Nimr is executed.

Lebanon’s Hezbollah has not been silent about al-Nimr either. The day after al-Nimr was sentenced to execution, the Lebanese resistance movement condemned the ruling as “unfair and politically charged.” In an earlier release, the group issued a statement that “The continued detention of this great scholar and prosecuting him for natural political activities comes while such rights exist for every individual and every scholar and expression of ideas and views is a natural right of all individuals, underlined by all international regulation and divine faiths.”

Protests against al-Nimr’s death sentence were also held outside of Saudi Arabia’s embassy in Yemen’s capital, Sana’a. Ibrahim Bader Al-Deen al-Houthi  the brother of Abdulmalik al-Houthi, the leader of Yemen’s Shi’ite Houthi rebels  wrote in an online commentary, “We warn Saudi Arabia against…harming Sheikh al-Nimr in any way.” He also declared that “if the Saudi authorities execute al-Nimr, it will be a criminal act that will not go unanswered.”

Iraqi Shi’ite militias  including Kata’ib Sayyid al-Shuhada (“The Battalion of the Sayyid’s Martyrs,” or KSS), Kata’ib Hezbollah (“Battalions of the Party of God”), and Asa’ib Ahl al-Haq (“League of the Righteous”)  have reacted as well. Asa’ib Ahl al-Haq’s political wing in particular warned that Saudi Arabia would face “consequences” for the verdict. Previously, KSS praised Bahraini Shi’ite militant groups’ attacks in the island kingdom, and Kata’ib Hezbollah (not the Lebanese group) launched assaults against U.S. armed forces in Iraq, citing Washington’s support for the Bahraini government during the Shi’ite uprising of 2011 as justification.

Saudi Arabia and Iran’s Rivalry

The flames of sectarian violence have wreaked havoc across the Levant and Arabian Peninsula. Bahrain, Iraq, Lebanon, Syria, and Yemen continue to serve as sensitive proxy battlegrounds in Saudi Arabia and Iran’s geopolitical rivalry.

Riyadh has backed Sunni forces in these countries with the intention of countering Tehran’s influence in the Arab world, which grew substantially after Saddam Hussein’s regime fell in 2003. The country played a pivotal role in sending its youth into Syria to wage a “holy war” against the secular Alawite regime in Damascus and its Lebanese ally Hezbollah.

Daesh’s rise to power last year, however, demonstrated that Riyadh’s sectarian foreign policy has backfired against the kingdom’s interests. Interestingly, while Saudi Arabia and Iran maintain opposing interests in Syria and Iraq’s political futures, the two states indeed share a common interest in defeating Daesh, which controls swathes of Iraqi territory near both countries’ borders. Recent diplomatic overtures between Riyadh and Tehran, following the 2013 election of the moderate Iranian president Hassan Rouhani, have prompted speculation that the mutual threat of Daesh will pave the way for a thaw in Saudi Arabian-Iranian relations.

Yet if a rapprochement between the two rivals is in the works, al-Nimr’s execution would surely derail it. If Saudi Arabia executes al-Nimr, which would make him the first Muslim cleric to receive the death penalty in the kingdom, Iranian officials would have to respond in some form, as the Islamic Republic fashions itself as the heart of modern day Shi’ism. Additionally, new threats to Saudi Arabia will arise from other countries on its borders as various groups who revere al-Nimr would feel obligated to strike against the state or its interests abroad.

Within the oil-rich Eastern Province, there is a possibility that Saudi Hezbollah (which is also distinct from the Lebanese group) could reemerge as a force capable of wreaking havoc, posing graver security challenges for the ruling monarchy. Indeed, in the late 1980s, Saudi Hezbollah bombed energy infrastructure in the kingdom and waged an assassination campaign that targeted Saudi Arabian diplomats in Pakistan, Thailand, and Turkey in response to the killing of hundreds of Iranian pilgrims who traveled to Saudi Arabia for the Hajj in 1987 and the beheading of four Saudi Hezbollah members.

As officials in Riyadh decide what steps to take toward al-Nimr, they must be cautious about the possibility of Shi’ite militias carrying out future attacks against the ruling monarchy. Indeed, reports have surfaced of Shi’ite militants striking first against Saudi security forces in the Eastern Province. If true, al-Nimr’s execution would only serve to exacerbate the dangerous state of relations between the Sunni monarchy and the kingdom’s 3 million Shi’ites at a time when Saudi Arabia faces a growing security threat from Daesh in Iraq and al-Qaeda in the Arabian Peninsula in Yemen.

Ideally, Saudi Arabia’s authorities will conclude that they must spare al-Nimr’s life to prevent sectarian unrest from further escalating in eastern Saudi Arabia and the greater Middle East. Until that decision is made, al-Nimr’s fate will hang like a sword of Damocles over the region’s already volatile geopolitical environment.

Giorgio Cafiero is the founder of Gulf State Analytics (GSA). Reprinted with permission from Foreign Policy In Focus.