On Monday, Irans powerful Guardian Council endorsed the Majlis resolution adopted the previous day to downgrade the countrys ties with Britain.
The speed with which the process gathered momentum conveys the message that it carries the stamp of a decision at the highest levels of the Iranian leadership.
That and the overwhelming mood of support for the move within the Majlis also indicate that the locus of power in Iran is shifting to a hard line.
The move includes expelling the British ambassador in Tehran and downgrading the representation to the level of charge daffaires.
By Tuesday afternoon, dozens of Iranian protesters forced their way into the British compound in Tehran, tearing down the Union Flag and throwing documents from windows.
A signpost has been put up in Tehran that can be ignored only at some peril.
The protesters raised three main slogans: Down with Britain, Down with America, and Down with Israel.
They carried photographs of Iranian scientist Majid Shahriari and the Islamic Revolutionary Guards Corps commander Major-General Qassem Soleimani.
Tuesday was also the first anniversary of Shahriaris murder, which was believed to have been carried out by Israels Mossad with the support of Britains Secret Intelligence Service, MI6.
Asymmetrical response But the tipping point must be Londons steps toward removing the Mojahedin-e Khalq (MKO) from the list of terrorist organisations.
The MKO has been responsible for some of the most devastating terrorist attacks in the history of the Islamic Republic of Iran.
Tehran holds the MKO responsible for more than 17,000 killings over the years.
The most celebrated were of course those of Ayatollah Muhammad Behesti (who was next only to Imam Ruhollah Khomeini in the pantheon of the revolutionary leadership) in June 1980 and of the popularly elected Iranian president Muhammad Rajayi in August of the same year.
The second terrorist strike came close to eliminating the entire revolutionary leadership under Khomeini.
It must be one of the quirks of modern history that Western intelligence has depended on the MKO, which practices an ideological mix of Marxism, nationalism and Islam, as the principal instrument to subvert the Islamic regime in Iran.
Iranian security personnel and Lebanons Hezbollah busted in a major counterintelligence operation in Beirut the entire network of the US Central Intelligence Agency in Lebanon and Iran.
The CIA was apparently using Lebanon as the gateway to penetrate Iran, given the relative freedom of movement between the two countries.
Through May and June, Iranian security officials arrested more than three dozen Iranians who were working for the CIA.
Their interrogation revealed that recent covert operations against Iran were the joint ventures of the CIA, Mossad and the MKO.
Thus the British move to rehabilitate the MKO (whose leadership is based in Brussels and is allowed to travel freely to the European capitals) has infuriated Tehran to no end.
It seems to be the real reason behind the present crisis.
Tehran is resorting to asymmetrical response by striking at the symbol of British power because it lacks the capacity to pay back to London in the same coin.
A deep chill is setting in with Irans ties with Britain.
The relationship has been a hugely troubled one historically, the high-water mark in recent history being the coup leading to the overthrow of the government of Mohammed Mossadeq in Iran in 1952, which is commonly attributed to the CIA but was actually the handiwork of MI6.
And Iran remembers it.
Iran knows better than most countries that Britain continues to be the brain behind Americas policies - be it toward Iraq, Afghanistan, Syria or Myanmar.
Britain will almost certainly take its grouse over the Iranian snub to the European councils and will seek a regional consensus in the Western world to make diplomatic moves against Iran in unison.
The predictable pattern will be that given the heightened feelings in London, such countries as Germany that have extensive involvement in Iran will fall in line.
All the same, it becomes an occasion to take the temperature on European unity when chips are down over the Iran situation in the coming months.
This, in a manner of speaking, will also be the trial run for the Middle East.
The lines are being drawn as the night of the long knives begins.
Everyone understands it.
And for the autocratic regimes in the Persian Gulf, there will be no corner to go and hide in.
The hurried visit by King Abdullah of Jordan to Israel shows the panic over the gathering storm.
Saudi Arabias robust efforts to divide the region on Sunni-Shia sectarian lines havent succeeded.
The Arab street will find it difficult to accept the Western push against Iran.
That is the thought worrying Abdullah most.
What if this mass indignation erupts in Jordan? The United States and Israel will no doubt work overtime in the European capitals to get the West to downgrade ties with Iran and if they succeed, they will beat the drums that Iran faces international isolation.
But it may have no value other than propaganda.
Clearly, Tehran has factored in the downstream diplomatic fracas that will follow by insulting Britain, and is nonetheless going ahead with its decision to downgrade ties.
So, what is on the Iranian mind? Some serious conclusions can be drawn.
First, Tehran estimates that a US-British-Israeli axis is in any case gearing up for a confrontation.
The strategic ambiguity - all options are on the table - no longer exists really, after the hardline policy speech by US National Security Adviser Tom Donilon at the Brookings Institution in Washington last week.
Evidently, Donilon spoke up for President Barack Obama, fully mindful of the criticality of an already supercharged Middle East situation: We have enhanced our significant and enduring US force presence in the region.
In addition, we have worked to develop a network of air and missile defences, shared early warning, improved maritime security, closer counterterrorism cooperation, expanded the programs to build partner capacity, and increased efforts to harden and protect our partners critical infrastructure.
The steps demonstrate unmistakably to Tehran that any attempt to dominate the region will be futile.
And they show the United States is prepared for any contingency .
President Obama has said as recently as last week, we are not taking any options off the table in pursuit of our basic objectives.
Second, Tehran estimates that this confrontation may take place within Obamas first term as president - because it may well ensure the success of his bid for a second term.
The manner in which the Obama administration jacked up the tensions with Iran almost in parallel with the commencement of his re-election bid hasnt escaped Tehrans attention.
Third, emanating out of the above, Tehran has little choice left but to take to the high ground, as it is no longer a matter of Iran being flexible on the nuclear issue or not, of Iran being conciliatory toward Israel or not, or of Iran being moderate on the Palestine problem and the Arab-Israeli conflict or not.
It is pure power play and realpolitik.
A similar situation arose in 1980 when Tehran couldnt care less anymore what the US and Britain thought of its revolution, and Tehran feels today once again that it is far better off without the British hanging about.
The Iranian historical consciousness still regards Imperial Britain as a poisonous serpent that every now and then crept up from India to devour the succulent Persian fruit.
Collective memory The animus against Britain comes out clearly in the statement issued by the student protesters who stormed the embassy: The embassy of the old fox should have been occupied much earlier.
Every free-minded Iranian whose heart is beating for this land and has observed the crimes of the old colonialism against Iran and the Iranians should know that occupation of the embassy of the old fox serves the interests of Iran and our countrys national interests.
The recent statements by Iranian military commanders have warned that Iran has known (and unknown) capabilities to retaliate if attacked.
By warning explicitly, it hopes to inject some rational thinking into the US-British-Israeli discourses that are bordering on delusional estimations regarding Irans policies and choices.
But Tehran senses the futility of trying to influence the undergirding of the Obama administrations disposition anymore in the near term.
In the Iranian estimation, Obama is simply not interested in hearing Irans narrative.
His obsessive concern is his 2012 re-election bid, and his campaign interests lie in diverting the locus of the political discourse away from his failings in mending the US economy.
A regime change in Syria and a move toward cracking down on the Hezbollah are just the kind of decisive leadership that he needs to project to get over the image that he leads from the rear.
With an amazing degree of belligerence, Donilon continued in his speech at Brookings: The end of the [Bashar al-] Assad regime [in Syria] would constitute Irans greatest setback in the region, a strategic blow that would further shift the balance of power in the region against Iran.
Tehran would have lost its closest ally in the region.
To be sure, the revolutionary mood in Tehran is developing against the regional backdrop.
Tehran links Donilons belligerence with the stationing of the nuclear aircraft carrier USS George H W Bush off Syria.
The US 6th Fleet is also patrolling the eastern Mediterranean off Syria.
The US and Turkey have asked their nationals to leave Syria.
Again, US Vice-President Joseph Biden has arrived on a surprise visit to Iraq, en route to Turkey on a mission to display US backing for Ankaras interventionist role in Syria.
Turkish Foreign Minister Ahmed Davutoglu hinted for the first time on Tuesday that his country was ready for an intervention in Syria.
According to Britains Daily Telegraph newspaper, a secret meeting was held in Istanbul last Friday between Turkish officials and representatives of the Libyan opposition to work out the logistics to bring Libyan fighters who were trained and equipped by the West to fight in Syria.
There are reports in the Russian media that the first contingent of 600 Libyan fighters may have already been transferred to Syria.
The dilemma facing Turkey and its Western allies is that the Syrian armed forces have overwhelmingly remained loyal to the regime.
Thus the fig leaf of Syrian resistance is unavailable, which in turn would expose the gamut of the outside intervention.
The Libyan fighters are expected to make up for this operational deficiency.
In short, the writing is there on the wall that a Western intervention in Syria led by Turkey is shaping up.
France has openly called for creating a European Union-backed humanitarian corridor that would allow Western intelligence and military advisers to move through Turkey into Syria and mastermind the regime change.
Turkey was specially invited to the EU foreign ministers meeting in Brussels on Tuesday.
All in all, Tehran is left in no doubt that the time has come to switch the Iranian nation into a revolutionary mode.
The intrusion into the British Embassy invokes archetypal symbols of defiance and resistance, which are embedded in the Irans revolutionary consciousness - especially when the collective memory about Britain is summoned.
It is Irans ultimate line of defence - as was the hostage crisis with the US in the months following the revolution when Iran came under siege.
Clearly, Obama, who has a panache for taking political gambles - and has so far won in a meteoric political career - is on a slippery path.
Syria is a hard nut to crack; Hezbollah is waiting in the wings; so is Hamas.
The odds are 50-50 that things may not happen the way Donilon tried to persuade us to anticipate, even if they may not be an exact replay of the outcome that horrified Jimmy Carter.
On Tuesday afternoon, the US-Iran standoff moved to a flashpoint.
Asia Times