The bitter sectarian rift between Sunni and Shia powers Saudi Arabia and Iran has not only poisoned their bilateral relationship but further inflamed the region's conflicts, from the bloody civil wars in Syria and Yemen to the sectarian strife in Iraq, Bahrain, Lebanon and elsewhere.
The brutal decision by the Saudis to execute dissident Shia cleric Sheikh Nimr al-Nimr, along with 46 others, is akin to pouring fuel on a raging fire.
Iran’s angry protests, however, including the storming of the Saudi embassy in Tehran by militants, and which have led to Riyadh and other Gulf monarchies severing diplomatic relations, will do little to appeal to the world community’s sympathies.
While the Saudi Shia community is undoubtedly oppressed, and by most accounts Sheikh Nimr was an advocate of peaceful change, Iran’s record on the death penalty at home is actually far worse than the Saudis. Last year, human rights groups estimate the Islamic Republic executed some 1,000 people including juvenile offenders, compared to the Saudis’ 157.
The sharp escalation of the conflict between Shia and Sunni branches of Islam has been a by-product of the Iraq war and the Arab Spring which shook up the seemingly entrenched regional order.
Proxy wars have seen Saudi tanks propping up the minority Sunni monarchy in Bahrain, and its aircraft battling Houthi Shia rebels in Yemen, with Iran supporting Syria's dictatorship. Tehran has also been angered by the Saudi handling of a stampede during the haj in September that left more than 2,400 pilgrims dead, including more than 450 Iranians, and by its monopolisation of control of this most holy of rituals.
There is a real danger that the fruit of the welcome ongoing rehabilitation of Iran in the world community is serving largely to feed existential fears in the Sunni-led kingdoms.
Instead of encouraging badly-needed reform and democratisation, royal families are battening down the hatches against the enemy abroad, fanning the flames of sectarianism. The non-Muslim world can do little but watch on and despair.