Five years on from the Arab Spring, revolutions and hopes for democratic transformation have been replaced by religious nationalism, trumpeted most loudly in the rivalry between two of the region's key players, Saudi Arabia and Iran. It is just five days since Saudi Arabia's 2 January execution of 47 men convicted of terrorism and sedition charges, including leading Saudi Shia cleric Nimr Al-Nimr. Prospects for the region, already reeling from civil wars, ongoing military campaigns and the biggest displacement of populations since World War II, already looks worse. Al-Nimr was arrested in 2012 for his vocal support of the anti-government protests in Saudi Arabia's Shia-dominated eastern province. A respected opposition figure in Qatif, the epicentre of the demonstrations, Al-Nimr was tried before a special criminal court. In October 2014 he was found guilty of a legion of charges, including sedition, disobeying the king, inciting sectarian strife, bearing arms against security forces and calling for the collapse of the state, and sentenced to death. The protests in early 2011, on the heels of the Tunisian and Egyptian revolutions, were the biggest in the history of the conservative Sunni kingdom. The mainly Shia protesters demanded the release of prisoners of conscience and activists, better living conditions and an end to what they said was their marginalisation in the oil-rich kingdom. Al-Nimr, who already had a history of brief detentions for demanding religious freedoms, raised the bar in 2012 when he became a vocal critic not just of the Saudi ruling family but of the Bahraini monarchy and Syria's Bashar Al-Assad. In a speech following the death of the Saudi minister of interior, Al-Nimr declared that the late minister's victims should be happy and wished the same fate on the Saudi and Bahraini monarchies and Al-Assad. Although 46 others — including two other Shias — were executed, it was Al-Nimr's execution that sparked protests by Shia demonstrators in Pakistan, Iraq and Bahrain. Iranian leaders condemned the execution in strong words. Iran's supreme leader, Ayatollah Ali Khamenei, issued a statement saying that Riyadh would face “divine revenge.” In Tehran, protesters set the Saudi embassy on fire on Saturday, and in Iran's city of Mashhad the Saudi consulate met the same fate. In a speech on Sunday, Hassan Nasrallah, leader of the Lebanese Shia Hizbullah movement, attacked Riyadh's rulers, accusing them of fomenting regional sectarianism. Riyadh was quick to respond. It severed all diplomatic ties with Tehran on Monday, cut trade links and suspended flights to and from Iran. The Saudi action was followed by Bahrain, Sudan and Kuwait recalling their ambassadors from Iran. The United Arab Emirates, which has billions of dollars' worth of trade relations with Iran, downgraded its diplomatic representation. While Riyadh's allies Qatar and Oman refrained from following their Gulf neighbours, Iran's regional isolation may intensify at the extraordinary meeting of Arab League foreign ministers called for Sunday 10 January by Saudi Arabia. Jordanian political commentator Labib Kamhawi says it would be wrong to interpret Gulf and Sudanese solidarity with Riyadh as a sign of Sunni alignment. “These countries have no real interest in escalating tensions with Iran. It is simple political calculation for them to side with Saudi Arabia,” he said in a telephone interview. The Arab region will reap no benefit from deteriorating relations with Iran, he added. This might explain the carefully worded condemnations of Egypt, Jordan, Morocco and Tunisia of the attack on the Saudi embassy. All four states stopped short of attacking Tehran. Algeria adopted an even more neutral position, expressing “sorrow” at the deterioration of already “complex” Saudi-Iranian relations. Ankara, Riyadh's non-Arab regional ally, refrained from expressing either its support for the executions or condemnation of the Iranian reaction. On Monday a Turkish government spokesman elaborated: “Saudi Arabia and Iran are our friends and we don't want them fighting because that's the last thing the region needs.” Al-Azhar, which condemned the attack on the Saudi embassy before the Egyptian Foreign Ministry, expressed its support for the executions. “Egypt could have employed stronger language critical of Iran but avoided doing so,” noted Ahmed Youssef, Arab affairs analyst and a professor of political science at Cairo University. An Egyptian, identified as 30-year-old Mohamed Abdel-Ati, was among the 47 men executed. According to the Egyptian Al-Watan newspaper, Abdel-Ati was 18 when he was arrested in 2003 following a police raid on his home in Mecca. Along with 12 others, he was charged with planning to carry out terrorist attacks in the kingdom. The Saudi-Iranian fallout has not only exacerbated Sunni-Shia tensions in the region but has complicated efforts to resolve the ongoing conflicts in Syria and Yemen. Last month Iranian and Saudi representatives for the first time engaged in direct talks in an attempt to forge a political solution to the Syrian conflict. Now the fate of UN-sponsored talks between the warring parties in Syria scheduled for later this month in Geneva is unclear. It remains to be seen how Al-Nimr's execution will fully resonate within the Gulf Shia community and how it will affect Iran's general elections slated for next month. The burning of the Saudi Embassy in Tehran served to shift domestic, regional and world attention from the mass executions. On Monday a US State Department spokesman said Washington will not be mediating between the two regional rivals, though he urged both Saudi and Iranian leaders to de-escalate. Washington condemned the embassy attack but remained silent on Al-Nimr's execution. While Russia and Turkey have both offered to mediate, and Tehran has formally apologised to the UN for the attack on the Saudi embassy, there is little sign of the fallout being contained. And observers are still struggling to understand the motives for the original trigger, the executions. “I think shock is the operative word,” says Saudi journalist and filmmaker Safa AlAhmad. “No one thought the government would go through with the executions.” AlAhmad's 2014 BBC documentary on the protests in Saudi's eastern province, and Al-Nimr's role in them, offered a rare glimpse of the kingdom's brief brush with the Arab Spring. Although the focus is now on Iran it shouldn't be seen as the sole target, says AlAhmad. “Saudis have their own internal calculations, including deflecting attention from major budget shortfalls by focusing on alleged security issues,” she said. Saudi's new king is still consolidating his rule. The Saudi-led military campaign in Yemen, now in its 10th month, has yet to bear fruit, oil prices are plummeting and Riyadh's plans to remove Al-Assad in Syria have been unsuccessful. “Clearly there are problems, and quite possibly Saudi Arabia felt pressured into acting,” said Youssef. “But the wisdom of expanding the conflict is questionable.” Executing both Al-Nimr and Al-Qaeda operatives appeared calculated to send a powerful domestic message, argued Youssef. “I believe domestic Saudi public opinion, especially Sunni, supports the executions and I find that to be a very dangerous approach.” Saudi-Iranian regional rivalry first escalated when Tehran furnished military and logistical support — including Hizbullah fighters — to Al-Assad after the Syrian uprising devolved into armed conflict. Riyadh views Iranian influence as a threat to its own role in the region and the Islamic world. Tehran, which has long had leverage in Iraq and Lebanon, saw its international isolation begin to reverse after it reached a deal in July to limit its nuclear programme in exchange for easing sanctions. Youssef believes the escalation has reached the “limits of what's possible”, for now at least. “There is always the impossible,” he added, “but we're not there yet.” Kamhawi, on the other hand, thinks Iran will resort to “military and political attrition” against Riyadh, further involving Saudi Arabia in Yemen and thwarting its plans for Syria and even Lebanon. Tehran, he pointsed out, has pressure cards to play in Syria, Iraq, Yemen and Lebanon while Riyadh does not. How the rivalry between Riyadh and Tehran will play out in the wake of the executions remains unclear, most observers foresee more bloodshed in Yemen and Syria. It is a far cry from the predictions of calmer times that were being voiced just a few weeks ago. “So many projections pointed towards solutions and pacification,” said Gamil Mattar, a pan-Arab political analyst and head of the Cairo-based Centre for Development and Futuristic Research. Russia was playing down tensions with Ukraine, Turkey with Israel, there were talks of a new unity government in Libya, groundbreaking developments in US-Iranian relations and serious efforts to end the conflict in Yemen. “Now the region is boiling,” he said, “and it looks almost deliberate.”