Hojjatoleslam Hesham Seimori, the resident mid-ranking Shi'ite cleric at the Fateme Zahra mosque in the Iranian city of Ahvaz near the Iraqi border, was a controversial figure. He was known for his anti-Saudi and anti-Wahabi preaching and as a staunch defender of policies propagated by the Shi'ite theocratic regime in Teheran.

Seimori's outspokenness and unconditional subservience to the central government in Teheran made him many enemies among the residents of the Shelang Abad neighborhood, an ethnic-Arab area where his mosque was based. On June 24, 2007, unidentified gunmen shot him dead outside his house.

Political assassinations are a rarity in the Islamic Republic, but Seimori's murder is further disturbing for Teheran given its potential to provoke sectarianism in the oil-rich province of Khuzestan that is pivotal to the Iranian economy.

Since 2005, Khuzestan has experienced a number of bombings of oil infrastructure and government offices, and the political atmosphere has not been this tense since the end of the Iran-Iraq War in 1988. Teheran has accused former Iraqi Ba'athists and Western intelligence agencies as instigating violence here, but never al-Qaida.

Three days later, as Seimori's family and friends gathered in his mosque to mourn his passing, they found CDs scattered around the building. The CDs contained a stark warning from al-Qaida stating that Iran should stop its support of Iraq's Shi'ites, and that it would otherwise be considered as a legitimate target for Sunni jihadists.

That message was repeated in an audio tape released on July 9, where Abu Omar al-Baghdadi, a purported leader of the al-Qaida-affiliated Islamic State of Iraq, gave Teheran an ultimatum until September 9 to walk away from Iraq and cease its support for Shi'ite parties or expect "fierce war" which would strike "every spot" where Iranians are found.

IRANIAN officials and media scantly noted the al-Qaida ultimatum, and most of the related reporting was by Farsi-language outlets based outside Iran. Teheran's silence can be explained by its desire to avoid panic among its public, given fears that the carnage in Iraq has the potential to spill over into Iran. The alternative view is that Teheran considers al-Qaida's threats mere bravado and untenable as the latter find itself growingly isolated among Iraq's myriad of militant groups.

While it is true that to deprive its Iraqi Shi'ite foes of Iranian patronage would be tantamount to a significant strategic triumph for al-Qaida in Iraq, to believe that ultimatums alone would chase Iran off the stage is to hugely underestimate Teheran's commitment to shape the future of post-Saddam Iraq.

Meanwhile, there is no evidence to suggest that Iraq-based Sunni militants perpetrated Seimori's killing. It is also very possible that the CDs were produced by a homegrown activist cell which has deliberately set out to antagonize the Iranian regime. Nevertheless, Teheran cannot entirely dismiss the threat of Sunni jihadists to its national security.

With the threat of US or Israeli attacks against its nuclear installations still looming, at least some Iranian officials will view inaction in the face of al-Qaida threats or violence on Iran's soil to be interpreted as weakness by Teheran's foreign adversaries, but also by other militant ethnic groups operating in Iran, such as Marxist Kurdish insurgents in Iran's west or Sunni Baluchi militants in the southeast.

AND THEN there is the economic necessity to protect the oil industry in Khuzestan from any kind of attack.

But Iran's options to deal with an al-Qaida threat on its turf are not uncomplicated. Excessive security measures in Khuzestan would further disgruntle the two million ethnic Arab minority, and be a step that would surely be provided as proof by Sunni Arab regimes of Teheran's Persian chauvinistic nature. Any military preemptive effort against its adversaries based inside Iraq - as Teheran is currently waging in Iraqi Kurdistan against PEJAK, an Iranian Kurdish insurgent group - bears the risk of pitting Iran squarely against the US military. Overt action against al-Qaida could also put a dent in the Iranian claim to be a guardian of the umma (Islamic nation), an ambition dear to the neo-Islamists in Iran and spearheaded by President Ahmadinejad.

While Teheran publicly professes a preference for a swift withdrawal of US "occupation forces" from Iraq, in reality the Iranian regime has to be concerned that the inability of the US to beat al-Qaida in Iraq could very well have severe repercussions for Iranian national security once the American military departs from Iraq.

An undefeated and still vehemently anti-Shi'ite al-Qaida could then redirect its efforts against the largest and most powerful Shi'ite state in the world, Iran.

This op-ed appeared in the Jerusalem Post on October 16th, 2007.
Javedanfar is coauthor of The Nuclear Sphinx of Tehran: Mahmoud Ahmadinejad and the State of Iran [1]. Vatanka is the security editor at Jane's Information Group.