As the United States considers its next step against Iran after an alleged plot to assassinate the Saudi Arabian ambassador in Washington was revealed this week, speculation is growing over what form the US response will take and the consequences the various options would have on security and stability in the Middle East and beyond.
US Vice President Joe Biden said on Wednesday that "nothing has been taken off the table" in regard to the possible action the US would take against Iran, after two men linked to Iran's security agencies were accused of planning to assassinate Saudi Ambassador Adel al-Jubeir on US soil.
US justice officials on Tuesday filed charges of conspiracy to commit terrorism against Manssor Arbabsiar, 56, a naturalized US citizen who also holds an Iranian passport and was arrested in September, and Gholam Shakuri, who was identified as a member of the Quds Force, a special covert unit of Iran's Revolutionary Guard (IRGC). Shakuri is still at large and thought to be in Iran.
Biden said that the US would be working to provide its allies with hard evidence in an attempt to present a solid case against Iran and formulate an international response.
This was thought to allude to expanded economic sanctions, the possibility of which increased on Thursday when it was revealed that the Obama administration was "actively" considering sanctioning Iran's central bank, a move that could severely damage Iran's economy and potentially provoke a strong response from Tehran.
The Obama administration appears to be convinced that that the orders to execute the assassination plot came from the highest level in Iran. If the US can convince its allies of this, harsher economic sanctions will follow, possibly through the United Nations structure.
A declaration of war?
However, if the plot was the work of the Quds Force, its orders would have been sanctioned by Ayatollah Khamenei, Iran's Supreme Leader of the Islamic Revolution. Such an order is already being considered a declaration of war by some in Washington and has raised the prospect of a possible unilateral military response from the United States.
"This brazen and audacious plot on American soil is evidence of the failure of the current 'soft power' policy of the Obama administration in dealing with Iran," Lt. Col. Bill Connor, former senior US advisor in Helmand Province, Afghanistan, told Deutsche Welle.
"Iran supports Hezbollah; it has been caught directly aiding Shia insurgents in Iraq and substantial indirect evidence points to Iranian involvement in Afghanistan. Rhetoric from top Iranian leaders has also made clear the intention to detonate a nuclear device in Israel."
According to Connor the latest plot should clearly show the international community why Iran poses a threat to the US, and why the West should take action before it's too late.
Jed Babbin, former US Deputy Undersecretary of Defense, is also an advocate of a direct response by the United States.
"This was an attack that was aimed at people within the United States," he told Deutsche Welle. "It would have killed American citizens as well as the intended targets. This would have been a direct action against the US and its sovereignty. So it would be well within our prerogatives to undertake action directly and quickly against some IRGC command centers - and we know where they are."
Amid the calls for an immediate response by the US, there have also been words of extreme caution. A number of analysts and security experts have questioned the link between the plot and the Iranian leadership, and have cast doubts over the alleged involvement of the Quds Force in a plan using Arbabsiar, a former used car salesman, and a Mexican drug cartel.
Doubts over Quds involvement
The unprofessional nature of the planning, the ease at which communications were intercepted and the manner of Arbabsiar's arrest in a sting operation does not equate with the image of the Quds Force as a highly-trained, covert special forces unit.
"I think the plot is possible, but some things are unusual and I am not convinced that all is exactly as we hear it," Prof. Volker Perthes, an Iran expert and director of the German Institute for International and Security Affairs in Berlin, told Deutsche Welle.
"Certainly, the Revolutionary Guards do have a history of terrorism abroad. This is what makes the story possible. But then they tend to be more professional. They wouldn't need to use an ex-convict used-car dealer and the Mexican drugs mafia."
Given the current unstable and volatile climate in the Middle East, a US attack on targets in Iran could have catastrophic effects, especially if the US were seen to be acting on behalf of Saudi Arabia or Israel, both of which have been agitating for Washington to take decisive action against Iran in recent years. However, it could still have less damaging consequences than if regional adversaries take matters into their own hands.
US covert attack possible
"Any response from the Saudis against Iran would be less destabilizing than it would be if the response against Iran was from Israel," Jed Babbin said. "Any response from Israel discernible to anyone outside of Iran's borders would trigger a fairly substantial war."
Should an attack by the US transpire, military experts believe a more clandestine retaliation would be more likely than an overt show of force.
"If there is to be a strike, the most likely would be covert," W. Thomas Smith Jr., a former US Marine and an expert on international terrorism and counterterrorism, told Deutsche Welle.
"And it would be less a punitive strike and more a utility strike by special operations forces with the primary objectives of eliminating the plot's operational leaders outside of the US, gathering key intelligence, and shutting down any connected developing sub-plots in the process."
Despite the clamor in some quarters for an attack, some analysts believe that the most likely response will not involve military action given the current volatility of the Middle East region and the US administration's policy of enagagement.
"War with Iran is highly unlikely with the current administration," Chris Carter, a regional director with the US Counterterrorism Advisory Team, told Deutsche Welle. "Even if evidence leads all the way to the Quds Force's commander, anything beyond sanctions would undermine the current administration's doctrine of diplomatically engaging enemies like Iran."
Author: Nick Amies
Editor: Rob Mudge