The US says its deployment of a carrier strike group and a bomber task force to the Middle East is intended as a warning to Iran against targeting American interests, directly or through proxies, but some former officials and experts say it also brings the risk of miscalculation and unwanted confrontation between the two countries.
Announcing the move on Sunday, US national security adviser John Bolton framed it as “a clear and unmistakable message to the Iranian regime that any attack on United States interests or on those of our allies will be met with unrelenting force”, but he also emphasised that Washington “is not seeking war with the Iranian regime”.
A US official told ABC that the deployment of the USS Abraham Lincoln Carrier Strike Group to the US Central Command region was expedited after "clear indications" of Iranian and proxy forces preparing for a possible attack on US troops.
Secretary of State Mike Pompeo was more specific in identifying the threat, saying that if “a Shia militia group or the Houthis or Hezbollah” carry out actions against US interests, "we will hold the Iranians – Iranian leadership directly accountable”.
The US statements have put the focus on Iraq, where it has about 5,000 troops, and its consulate in Basra which was attacked by a pro-Iranian militia last year.
Republican Senator Marco Rubio joined the chorus of warnings to Iran on Monday against attacks on Iraqi soil, saying the US would not distinguish between Shiite militias in Iraq and the Iranian Islamic Revolutionary Guard Corps that controls them. "Any attack by these groups against US forces will be considered an attack by Iran and responded to accordingly,” Mr Rubio tweeted.
But critics of the administration saw Mr Bolton's statement as a step closer to confrontation with Iran. Former US negotiator Wendy Sherman questioned Mr Bolton's motives. "Bringing us war with Venezuela and with Iran? Never saw a war he didn't want to wage. Where is @realDonaldTrump?" Ms Sherman tweeted.
Although deterrence is the primary goal, "this kind of belligerence also increases the risks of miscalculation", Ali Vaez of the International Crisis Group said. "This is a routine deployment that John Bolton is trying to exploit as a credible military threat against Iran," he told The National.
But Mark Dubowitz, the chief executive of the Foundation for Defence of Democracies, supported the idea of deterrence.
"The message is to reinforce the credible threat of overwhelming American force if the regime in Iran strikes US assets or allies," he told The National. "If the past is prologue, the regime backs down in the face of credible American military power and advances when it believes they can target Americans or American allies and get away with it."
Alex Vatanka, a senior fellow at the Middle East Institute, said the carrier deployment was "not necessarily a beginning of a wider conflict”, with Iran more interested in showing off its reach, and perhaps retaliating indirectly to US sanctions through proxies.
“The Iranian media today is gloating and showcasing missiles by Islamic Jihad targeting Israel [from Gaza], this is unusual,” he said. “It shows Iran is flexing its muscle, saying 'as we are under pressure, we have ways to get back at Israel'.”
The more immediate interest for Iran, Mr Vatanka argued, is in re-examining its commitments under the nuclear deal. President Hassan Rouhani is expected to make an announcement this week on scaling back Tehran’s commitments following the US termination of waivers on Iranian oil purchases, and its terrorist designation of the Revolutionary Guard.
“The Iranian leadership is very cautious not to provide pretext for military confrontation … but it still has no answer how to deal with the US,” Mr Vatanka said.
Being on the edge without engaging in direct military conflict is likely to remain the status quo between the US and Iran for the foreseeable future, he said.