© GettyHouthi fighters in Sana'a.
The biggest danger to the al-Saud family which dictatorially rules over Saudi Arabia is the proven validity of an alternative Islamic system. The Islamic Republic of Iran has such an alternative system and its reintegration into the world after the nuclear deal shows its validity. Some people and Islamic scholars in Saudi Arabia might get the idea that they also could also have a system where every vote counts and policies are decided at the ballot box. This without a kleptocratic, dictatorial family and, importantly, without doing away with their core Islamic values. This, not religion, is why the Saudis have fought Iran since its revolution in 1979 and why they try to curb its influence wherever they can. The al-Sauds fear for their family and its sinecures.
That Saudis, together with Israel, tried everything to sabotage the nuclear deal. They want Iran back in the isolation box. But it is now too late. I have not read one piece in "western" media today that was negative on Iran and/or positive on Saudi Arabia. The wind of international politics has changed and it is now Saudi Arabia that comes under pressure. The impulsive reaction of the current Saudi rulers is to escalate and escalate even more and to fight Iran wherever it is present, like in Iraq, Syria and Lebanon, or even where it is not present like in Yemen.
While the Saudis claim that Iran supports the Houthis in Yemen there is not the slightest proof for that assertion. There have been no Iranians found in Yemen and no Iranian weapons. The Houthis the Saudis fight in Yemen are not Shia like the Iranians but are nearer to Sunni Islam than to Iranian 12er Shia. There has been no evidence that Houthis have received anything from Iran and all stories about Iranian weapon shipment to Yemen turned out to be false.
This is now likely to change.
After the killing of al-Nimr some Iranian hardliners organized a mob that stormed and ransacked the Saudi embassy in Tehran. This was an attack on what they see as appeasement policies of the Iranian President Rouhani. It was stupid of the Rouhani administration to not have foreseen such a move and increase protection for the embassy. It is now bending over backwards to apologize for the incident but to no avail.
The Saudis cut diplomatic relations to Iran and pressed Bahrain and Sudan to do the same. The Bahraini rulers need Saudi protection and Sudan the Saudi money. The UAE only lowered its diplomatic presence in Tehran from ambassador to chargé d'affaires. Interestingly the other Gulf countries did not follow the Saudi decision. The Saudis also stopped all civil flights between Iran and Saudi Arabia and forbid their citizens to visit Iran. Business between the countries will be stopped. Iranians on pilgrimage to Mecca are still welcome.
It is unclear what this is supposed to achieve. What could Iran reasonably do that would let the Saudi rulers retract these measures without losing face? This was another impulsive and erratic move that only hurts the Saudis people and the ruling family's international reputation.
More dumb moves are expected. The Saudis will likely up their proxy fight against Iran in Syria and possibly also in Iraq by giving more weapons and financial support to Jihadists of all strife. A new government in Lebanon, on which Iran and Saudi Arabia had recently agreed, is now again far away. The Saudis will also try to escalate the fight against the Houthis and their imaginary Iranian support in Yemen. But after nine months of bombing Yemen's infrastructure to dust there is little to escalate. All ground attacks by the Saudis and their various hired proxies have been fought to a standstill.
This then is the place where Iran can escalate in response. It has the technology and know-how to hand the Houthis some serious missile capabilities. Such missiles would allow them to achieve pinpoint hits on Saudi targets. The whole southern Saudi Arabia would then become a Houthi shooting range. Saudi Arabia would have to file for peace or would have to evacuate significant parts of the country.
The al-Nimr execution and the diversion of the Saudi public to strife with Iran will help the Saudi rulers to calm down internal disturbances. But the escalation comes at significant international political costs and may end up, via Houthi missiles, to increase the internal problems the Saudis are so keen to avert in the first place.
Comment: The Saudis were clearly banking on causing an uproar. While the Iranian government remained stoic, the Iranian vandals who set the Saudi embassy aflame gave the Saudis the response they wanted. Their swift and hyperbolic response - severing diplomatic ties, stopping civilian flights, cutting business - suggests it was planned in advance. The NATO-Gulf States bloc just won't quit. Now they'll be fighting Russia by fighting Iran, in Syria. Anything but dealing with the real problems facing the region: ISIS and the Saudi Wahhabi soil in which it was nurtured.