The current diplomatic crisis between Saudi Arabia and Iran reflects a deep and growing geopolitical confrontation in the Middle East. Iran, the regional enemy of the United States since the 1979 revolution, is no longer a pariah state since the July 2015 nuclear agreement . Since 1945, Saudi Arabia has been the oldest American ally in the area. An Obama facing his last year in Washington will have a hard time appeasing the rivalry between the Saudi economic muscle and the huge Persian historical-cultural wealth and its growing military power, which will benefit this year from the resumption of oil sales.

Shiites and Sunnis are all Muslims. Their differences are not doctrinal, although there are different theological and jurisprudential interpretations on some non-essential points of Islam. Their division dates back to the very beginning of Islam and was due to the politico-religious question of who should succeed the Prophet. The Shiites (Ali's party) said it should be his son-in-law Ali and then Hussein, Muhammad's grandson, both killed in battle by the Umayyads. The latter led the caliphate and the Sunni arm (the orthodox Islamic version), the most numerous since then and until today: out of 1500 million Muslims, 1300 million are Sunnis. Historically there were periods of internal wars and peace. Today, division and war prevail between the Sunni and Shia nations of the Middle East.

Iran is Shia and Persian. Saudi Arabia is Sunni and Arab. Two different races have a shared religion, but practiced differently and with mutual accusations of being infidels, the worst insult one Muslim can receive from another.

Saudi Arabia is a Sunni country with a Shiite minority concentrated in the eastern part of the country, precisely the most oil-rich. There, Nimr al-Nimr was arrested in 2012 for inciting rebellion against the Saudis, in the context of the failed Arab Spring that began in Tunisia a year earlier. To crush any semblance of reform in tiny Bahrain, Ryad had intervened militarily in that neighboring country, and was not willing to have a prestigious Shiite member of the clergy create any trouble for him inside the kingdom. Ryad sentenced Nimr to death in October 2014. His execution this past January 2, along with 46 other convicts (many of them Sunni Saudis linked to al-Qaeda), was intended to prevent attention from falling on the rebel member of the clergy Shiite. This purpose has blown up, showing the precariousness of the calculations and the tension of the powder keg that the Middle East has become.

The execution reveals Saudi confidence in controlling the outrage of the minority Shiite Saudis, upset by the political discrimination they face in the country and hit by suicide terrorist attacks on Shiite mosques twice in 2015. Jihadist attacks aimed at inflaming the already strained relations between the Shiite minority and the Riyadh government. In other words, to provoke a Shiite revolt within not only the Saudi Kingdom, but also within the most energy-rich region, something that has not yet occurred.

However, what jihadism has not achieved, the elimination of al-Nimr can achieve. The storming and burning of the Saudi Arabian embassy in Tehran has broken or damaged the diplomatic relations of several Gulf countries with Iran and exacerbated the unease of Shiites in Saudi Arabia. But the consequences may be even more serious.

Negotiations on a political transition in Syria will thus be greatly complicated. Iran and Saudi Arabia had agreed to sit at the same table in December to discuss the matter. In Syria, both countries are targeting and supporting respectively the al-Assad government and some of the rebel groups. In turn, this difficult agreement in Syria conditions the resolution of the political problem in Lebanon, a country that has been living without a President since May 2014, and where Persians and Saudis also intervene through the economic and political ties created with Hezbollah and the Lebanese Sunnis.

At stake is Saudi Arabia's ability to organize an Arab-Muslim alliance against the Persians. However, a pact based on petrodollars can work with Sudan or Egypt, whose economic dependence on Saudi Arabia is undeniable as highlighted by the $3 billion loan signed on January 5. But not with Turkey or Pakistan, whose national interests make them more reluctant to be absorbed by the Saudi diary , as seen by the refusal of both countries to put military troops in the war Saudi Arabia is fighting against its southern neighbor Yemen, where an Iranian-backed Shiite minority has failed to be defeated after 10 months of war.

At final, the rivalry between Iran and Saudi Arabia is much more than a passing diplomatic crisis. It is an entrenched politico-religious conflict, more difficult to resolve than winning the war against the Islamic State. A confrontation that weighs down that part of the planet and affects our world much more than we Westerners can imagine, more concerned about terrorism in our country (now that we are celebrating the anniversary of the January 7 attacks in Paris) than about what is happening thousands of kilometers away from our borders.