WASHINGTON The U.S. Navy has been moving its massive aircraft carriers in and out of the Gulf for decades, but when it sails through the Strait of Hormuz again, there will be extraordinary attention on what the Navy considers a mostly ordinary maritime maneuver.
Iranian officials earlier this month bluntly warned a U.S. carrier not to return to the Gulf and have threatened to block the strait, spooking oil markets and raising the specter of a U.S.-Iranian confrontation.
But rhetoric aside and barring a miscalculation on either side, U.S. officials tell Reuters they don't believe that the next carrier voyage through the narrow strait is likely to trigger a violent exchange with Iran. That is a view shared by U.S. analysts.
The U.S. military does not envision any special steps at this point ahead of the next carrier trip through the strait, beyond the lengthy protocols Navy carrier strike groups would follow anyway when heading through the world's most important oil shipping lane, officials say.
"I don't foresee the next (carrier entry) being any different than the regular ones we've been doing for the last 20 years," one U.S. defense official said.
A different U.S. official told Reuters that the United States expected the next transit through the strait to be routine, "and we hope that the Iranians do too."
There hasn't been a U.S. aircraft carrier in the Gulf since the USS John C. Stennis exited at the end of December. On January 3, Iran warned the Stennis not to return -- comments interpreted by some observers in Iran and Washington as a blanket threat applying to any U.S. carriers.
"I recommend and emphasize to the American carrier not to return to the Persian Gulf," Iran's army chief, Major General Ataollah Salehi, said. "We are not in the habit of warning more than once."
Islamic Revolutionary Guard Corps commanders have endorsed Salehi's comments, saying that the United States should keep its carriers away from the Gulf -- international waters that the Pentagon says it has no intention of abdicating.
But that doesn't mean Iran is ready to take action, U.S. experts say, even at a moment of heightened tensions between the United States and Iran.
"I don't think they're going to risk it. I think they're still trying to send signals and bluffing," said Bruce Riedel, a former senior CIA expert on the Middle East.
SOONER OR LATER
The Pentagon, citing operational security, will not say when the next carrier will transit the Strait of Hormuz. But officials have assured that it's only a matter of time.
On Thursday, the military appeared to take another step that could pave the way toward another passage through the strait, repositioning its powerful naval assets in the region.
The USS Abraham Lincoln carrier strike group arrived in the Arabian Sea to replace the Stennis, which moved into the Indian Ocean.
Now the Lincoln and the USS Carl Vinson carrier strike groups are operating in the Arabian Sea under the command of the Navy's 5th Fleet, which has the option of directing carriers into the Gulf.
The U.S. Navy is accustomed to drawing the attention of Iranian naval forces whenever one of its massive aircraft carriers pass through the strait.
Indeed, predictions that "nothing out of the ordinary" will take place doesn't exclude the kind of posturing by Iranian naval forces that U.S. vessels have become accustomed to seeing. That includes the fast approaches by small Iranian Revolutionary Guard Corps boats witnessed earlier this month.
But even those incidents involving armed IRGC boats weren't seen as hostile, U.S. officials say. U.S. military video of those incidents can be seen here: here
U.S. carrier strike groups carry extraordinary firepower. The formations include at least one cruiser and a destroyer squadron, as well as an air wing complete with fighter jets. They are also full of sensors to help monitor positioning of foreign ships - meaning they could detect unusual Iranian ship movements.
"I'm not saying it's no big deal, but it's so much part of the routine that we follow and have followed for such a long time," said retired Admiral Gary Roughead, who headed the Navy until September. He was referring to strait transits anywhere in the world, not just through the Strait of Hormuz.
"Even when I was commanding a cruiser back in the Gulf, it was the same way. I mean, you prepare, the sensors are up, and you really pay attention to what's going on."
Still, any usual activity -- while not expected -- also cannot be ruled out and could further heighten tensions between the United States and Iran.
"Routine in a Navy sense is: be ready for anything," said Bob Nugent, a retired naval officer and now a defense industry analyst.
Iran has threatened to close the Strait of Hormuz, used for a third of the world's seaborne oil trade, if pending Western moves to ban Iranian crude exports cripple its lifeblood energy sector, fanning fears of a slide into wider Middle East war.
The United States says it will not allow Iran to block the strait.
Iran's Islamic Revolutionary Guard Corps is expected to conduct a naval exercise focused on the Strait of Hormuz in the next several weeks, which could further exacerbate tensions.
Rear Admiral Ali Fadavi told the Fars News Agency earlier this month that the upcoming exercises would be the seventh staging of an annual drill called "The Great Messenger" and would be "different" from previous ones, without elaborating.
There are other sources of friction. Iran started an underground uranium enrichment plant and sentenced an American to death for spying. Washington and Europe have stepped up efforts to cripple Iran's oil exports, and Tehran has blamed Israel for the killing of an Iranian nuclear scientist.
The United States and the Pentagon in particular have been trying to keep a lid on tensions with Iran, and been careful to publicly stress that it is not altering the posture of U.S. forces in the region because of the latest rhetoric from Tehran.
Defense Secretary Leon Panetta on Wednesday said no "special steps" were being taken at this point to bolster American forces in the region because the U.S. military already had a robust presence and was prepared to deal with any challenge from Iran.
"I don't think they want to do anything that increases the march towards conflict. And that's how I interpret this," Riedel said, asked about Panetta's comments.
"They don't want to ratchet it up anymore than they absolutely have to."
(Additional reporting by Andrea Shahal-Esa and Tabassum Zakaria in Washington and Parisa Hafezi in Tehran; Editing by Stacey Joyce)