The many factors that are contributing to an increase of tension over Iran's nuclear ambitions were noted in the previous column in this series. They include an explosion at an Iranian missile-plant, the capture of a CIA surveillance-drone, the rhetoric of Republican politicians in the United States, and a hawkish speech by the diplomatic insider and Barack Obama's former adviser on middle-east issues, Dennis Ross (see "America, Israel, Iran: war in focus", 15 December 2011).
The column noted that - Ross's informed views notwithstanding - the perception of many analysts is that the Obama administration does not anticipate a military confrontation with Iran. This judgment has been reinforced by the remark of the US defence secretary Leon Panetta that a war with Iran could have dangerous consequences.
Amid these circumstances and signals, the column highlighted a longer-term strategic issue that might transcend more immediate concerns: the likelihood that Iranian influence in Iraq after the US troop withdrawals, and Washington's fear of Iranian regional power, might both increase to the point of confrontation.
The past week has seen three developments that bear on this argument. The first is the attempted arrest in Iraq on terrorism charges of the leading Iraqi Sunni politician and the country's vice-president, Tariq al-Hashemi. He has sought refuge in Kurdish Iraq, with his pursuer - Iraq's (Shi'a) prime minister, Nouri al-Maliki - requesting that the Kurds hand him over to the Baghdad authorities.
Whatever the basis of the allegations, the incident appears a case of a Shi'a-dominated government consolidating its (sectarian) power at the expense of Iraq's Sunni minority - even to the extent of abandoning the power-sharing process (see Tim Arango, "Prime Minister Puts Power-Sharing at Risk in Iraq", New York Times, 22 December 2011). The greater scope for Iranian influence in turn worries the six Arab states that form the Gulf Cooperation Council, which accuses Tehran of interfering in their internal affairs (see Jumana Al Tamimi, "GCC tells Iran to stop meddling", Gulf News, 21 December 2011). The potental of these tensions to deteriorate is shown by the coordinated multiple bombings on the morning of 22 December which killed at least sixty-three people and injured over 130.
The second development is an apparent change of emphasis in Washington, again reflecting a contribution by Leon Panetta. In an interview with CBS News, he both refused to rule out military action designed to prevent Iran developing nuclear weapons (while on this occasion omitting mention of the risks of such action) and expressed a belief that Iran could have a nuclear weapon within a year and perhaps even sooner (see Dan de Luce, "Pentagon Downplays Panetta Remarks on Iran, Nukes", Agence France-Presse, 20 December 2011).
In the immediate aftermath, Pentagon sources qualified these remarks; but the next day brought a further shift when the chair of the US joint chiefs-of-staff, General Martin Dempsey, said that "the US military had reached a point where they were ready to execute force against Iran if necessary" (see Amy Willis, "US military 'ready to engage in a conflict with Iran'", Telegraph, 21 December 2011). Dempsey does acknowledge the risks that a war would entail, but his comments form part of an unexpected change in attitude in Washington.
The third development is probably the most significant: the serious economic crisis now facing Iran, the result both of the impact of sanctions and economic mismanagement by the Mahmoud Ahmadinejad regime. The most striking indicator is the collapse of the Iranian rial's value against the US dollar: from around 7,000 rial to the dollar in October 2011 to 15,150 at the end of trading on 20 December (see Rick Gladstone, "As Further Sanctions Loom, Plunge in Currency's Value Unsettles Iran", New York Times, 21 December 2011).
It is possible that the impact of sanctions and the more hawkish utterances coming out of Washington run in deliberate parallel, part of a strategy that combines economic and military pressure to encourage the Iranian government to open up on its nuclear ambitions and reach an acceptable settlement. The US's effort further to tighten the sanctions process via the United Nations Security Council suggests that a coordinated approach is in train (see "US urges greater Iran sanctions implementation", CBS News, 22 December 2011).
This would be a very risky approach, especially given the complexities of the power-struggles in Tehran involving three groups: the Ahmadinejad regime, the theocratic leadership under Ayatollah Ali Khamenei, and the Iranian Revolutionary Guards Corps (IRGC). Among these contending circles are at least two forces that might in fact find useful a military confrontation with Israel or the United States (or indeed both).
The IRGC would see an attack by an external enemy as an opportunity to consolidate its role in Iranian society as the protector of the revolution, a role that has slipped in recent years, and thus enhance its own status. Ahmadinejad would see an assault as a welcome diversion from the domestic economic situation, and focus energies on ensuring that Iranians rally round the leadership as their country comes under fire.
These scenarios do not make war imminent or inevitable. But they do suggest that a move to a more uncertain period is occurring, where tensions can rise rapidly - especially if vested interests seek to raise them, perhaps even to the extent of precipitating war. There is the further risk that incidents outside Iran - in the western Gulf emirates, in Iraq, involving Hizbollah in southern Lebanon, through Israeli actions, or by sheer mistake or misunderstanding - could spark uncontrollable conflict.
There are too many examples of crisis-escalation by miscalculation to regard this situation with equanimity. The early months of 2012 might still see more rational engagement, something certainly to be hoped for. But equally they could see a sudden crisis erupt in a way that soon becomes dangerous and even catastrophic.