The Iran-Saudi proxy war that has played itself out in West Asia ad nauseam has reached a critical mass, with Iran dropping all pretence and hinting at Saudi Arabia's influence in the "ISIS attack" that left 12 people dead in Tehran.
Iran and Saudi Arabia are enmeshed in no less than three proxy wars which are panning out simultaneously in Iraq, Syria and Yemen, among other flashpoints.
Some of these are at a tipping point, with the Islamic State's desperation increasing as it has ''lost almost a quarter of the territory it controlled in Iraq and Syria over the past one year''.
Despite Iran's proactive role against IS in both Iraq and Syria, the Sunni jihadists had not thus far carried out any attacks inside Iran.
But Tehran was apparently on IS radar and according to western media reports, it had even released a rare video in Persian in March, warning that it ''will conquer Iran and restore its status as a Sunni Muslim nation''.
Incidentally, IS has strong Wahabbi roots - a fundamentalist sect that has been allegedly patronised by the Saudis.
The Americans, of course, are a permanent fixture in all these battle zones and willing accomplices of the Saudis.
Matters escalated when a crusader named Donald Trump came along, patted the Saudis on the back and muddied the waters.
Even though most perpetrators of 9/11 were Saudis, Trump, the orange knight in the shining armour, is convinced, or at least he is out to convince the world, that Iran is responsible for all that is going wrong in West Asia - from Lebanon to Iraq to Yemen.
The declaration that emanated from Riyadh after Trump's visit had stated as much and even discussed the possibility of creating a joint force - ostensibly to fight terror - in the first sign of a formal Sunni gang up against Iran.
Tehran, of course, is no babe in the woods: it had upped the ante recently, blaming Saudi Arabia's Wahhabi brand of Sunni Islam and its funding for most terror strikes in Europe, including the attack in London.
Curiously, this all-encompassing dirty war - that has played havoc with the destinies of several nations in West Asia - has a lot to do with the "paranoia" of the Saudis who have a chronic mistrust of the Iranians.
The most recent example of this is Qatar, which Saudi Arabia is trying to "fix" for its "bonding" with Iran. In a bid to isolate Doha in the Arab world, a motley group led by the Saudis even snapped all diplomatic links with Qatar and accused it of funding the Iran-backed Houthi rebels in Yemen.
The move had Trump's blessings and the US president spilled the beans when he announced that Qatar's isolation could be "the beginning of the end of the horror of terrorism". This, unmindful of the fact that the US has one of its largest air bases in Qatar, but Trump cares little for such niceties.
The Islamic State, by carrying out the terror strikes in Tehran, hopes to draw the entire Shia-Sunni world into the simmering sectarian fires. No wonder it chose to strike at the Iranian parliament and the shrine dedicated to Ayatollah Khomeini, both potent symbols of modern day Iran.
Given the Wahabi roots of the IS, that is understandable - they have a pathological hatred for the Shia Iranians whom they consider infidels or apostates.
But the IS has more than just pathological or theological reasons for wanting to square up with the Iranians. Tehran is proving to be a kill joy in both Iraq and Syria: its support to Iraqi forces and Bashar al-Assad's regime in Syria could trip the IS in its dream run to the Caliphate.
In fact, some media reports suggest the IS is finding the going extremely tough in both Mosul and Raqqa, which possibly manifested in the terror strikes in Tehran.
Interestingly, Iran and Saudi Arabia have a lot in common: both are theocracies, both are trying to wrest control of the region, both wish to control the oil cartels, and both accuse each other of being the fountain head of terror.
Both also have a Sunni and Shia minority, respectively, which complicates matters. The Saudis are again extremely paranoid about their Shia minority, ever more so after the Iranian Revolution.
Or at least the Saudis want that the sectarian fires keep smouldering so that they have a tenacious grip on the region.
Shia Iranians are less pensive about the Sunni minority getting restive but may have reason to worry now, if it is established that the IS is behind the attack.
There have been other face-offs too but Saudi Arabia and Iran have stopped short of engaging each other directly. All that might change, now.
Sometime back, protesters in Tehran had stomped through the Saudi embassy, indulging in acts of vandalism and arson. Iran had then looked the other way and the Saudis had retaliated by snapping diplomatic ties.
Predictably, the Saudis decided to pay back and not necessarily in kind. There was a mass execution and among those slain was one Nimr-al-Nimr, a prominent religious leader from Saudi Arabia's Shia minority.
Nimr's arrest in 2012 and subsequent execution in January 2016 perhaps escalated the Saudi-Iran tensions which later manifested in the two other theatres of war: in Syria and Yemen.
According to some West Asia experts cited in the western media, it was the uprooting of the Saddam regime in Iraq that disturbed the equilibrium in the region and led to both Saudi Arabia and Iran rushing in to ''fill the vacuum''.
Since then, both sides have spared no effort - overt and covert - to court tottering regimes, adding to the chaos in the region.
Saddam's ghost might be catching up with the US just as the sectarian war - which has a life of its own - is catching up with Saudi Arabia and Iran. The IS may be the catalyst.
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