The United States hasn't lost an aircraft carrier to hostile action since 1945, when the USS Bismarck Sea, a small escort carrier, was hit by a pair of Japanese kamikaze planes in February 1945, seven months before the end of World War II.
In the seven decades since, the giant warships -- floating cities powered by nuclear reactors that boast scores of aircraft, an array of advanced weapons systems and thousands of crew members -- have roamed the world's seas as the ultimate projection of American sea power.
That nautical pre-eminence makes the carriers attractive military and rhetorical targets for U.S. foes, including Iran, which made headlines last week by announcing it was building a full-scale mock-up of the nearly 1,100-foot-long USS Nimitz to train against and that carriers in the Persian Gulf would be singled out in the event of a war -- a notion that some military analysts believe China had embraced as well.
Adm. Ali Fadavi of the Iranian Revolutionary Guard's naval forces told the country's semi-official Fars news agency that the carriers' size makes them "easy targets" that could be sunk quickly.
"[Americans] know nothing. We have been making and sinking replicas of U.S. destroyers, frigates and warships for long years, and we have sunk the replica of their vessels in 50 seconds through a series of operational measures," Adm. Fadavi said. "We practice the same drills on replica aircraft carriers because sinking and destroying U.S. warships has, is and will be on our agenda."
In dismissing the saber-rattling, U.S. Navy and Pentagon officials have pointed out that sinking a replica and a real ship are far from the same thing.
Lt. Joe W. Hontz, a spokesman for the Navy's Fifth Fleet, based in Bahrain on the Persian Gulf, said the fleet has one carrier, the USS George H.W. Bush, operating in its area of responsibility, which also includes the Arabian Gulf, the Red Sea, the Gulf of Oman and parts of the Indian Ocean. The ship operates as part of a strike group that includes a guided-missile cruiser, two guided-missile destroyers and a destroyer squadron.
In a statement, Cmdr. Jason Salata, a public affairs officer for the fleet, said Iran's mock-up will have "zero impact on U.S. Navy operations in the gulf."
"Firing weapons at a stationary structure floating on pontoons is not a realistic representation of having the capability to target a 100,000-ton warship, with organic defenses, maneuvering at speeds in excess of 30 knots," Cmdr. Salata said.
"This is kind of a unique story, which is why it's getting a lot of legs," said Eric Wertheim, a defense consultant, specialist in international navies with U.S. Naval Institute and author of "Combat Fleets of the World," a reference book now in its 16th edition.
"It doesn't change the dynamic in any way. ... I don't think that our carriers are in danger of going to the bottom tomorrow because they are exercising on a mock-up."
Mr. Wertheim said the U.S. Navy has been dealing with the threat of Iran for more than 30 years, including Operation Praying Mantis in 1988, when American warships destroyed Iranian oil platforms and ships in retaliation after a U.S. guided-missile frigate, the Samuel B. Roberts, was hit by an Iranian mine in the Persian Gulf.
Since then, Iran has been working to modernize its weaponry, including small, swift missile boats used for "swarm attacks" on larger vessels, Kilo-class Russian submarines, smaller "midget submarines" and Chinese-supplied anti-ship missiles, Mr. Wertheim said.
He added that the Iranian Navy has no ship bigger than a frigate, a warship of about 4,000 tons that is smaller than a destroyer.
"The Iranian Navy's capabilities are not first class," Mr. Wertheim said. "They'll get their stuff from wherever they can. They even are modernizing stuff the U.S. and the U.K. sold them decades ago."
Iran has also boasted of the capabilities and firepower of its own drones on state television.
"I think it's fair to say that the Iranian Navy could be a thorn in the side of allied forces, and they would be able to possibly inflict a bloody nose or so under the worse-case scenario, but their naval power would be very quickly overwhelmed," Mr. Wertheim said, partly as a result of U.S. air superiority.
"It doesn't mean they can't do harm, it just means the endgame is very unlikely to be in doubt," he said.
Michael O'Hanlon, a senior fellow with the Center for 21st Century Security and Intelligence and director of research for the Brookings Institution's foreign policy program, agreed that Iran's warships and submarines wouldn't survive long during a "significant military operation" by the United States.
"However, that doesn't mean the situation would be easy under all circumstances," Mr. O'Hanlon wrote in an e-mail, citing the threat of an ambush before or as a conflict begins, the hazard posed by sea mines hidden near the Strait of Hormuz, the entrance to the Persian Gulf, and small boats armed with anti-ship missiles. "They could, in other words, 'go guerrilla' on us, with some considerable risk of hurting warships and/or oil tankers."
The scenario that should worry the American fleet, Mr. O'Hanlon said, is that presented during a 2002 war game in the Persian Gulf, during which an opposition force commanded by a retired Marine general successfully used swarm boat tactics and missile barrages to "sink" 16 U.S. ships, including an aircraft carrier, The New York Times reported.
Mr. O'Hanlon said in the event of a conflict, U.S. carriers would be best positioned just outside the Persian Gulf.
"They are protected fairly well against aircraft and small numbers of missiles, but the best defense is always to operate out of range of plausible enemy threats, and as such, I doubt they'd enter the Gulf during a war," he said.
Aircraft carriers travel in battle groups that generally include frigates, cruisers and destroyers that screen and protect them with anti-surface, anti-aircraft and anti-submarine systems, providing an outer layer of defense in addition to the carrier's own considerable armament.
"Aircraft carriers are probably the most-protected ships in the world," Mr. Wertheim said, adding that the U.S. Navy's 10 Nimitz-class carriers, which weigh nearly 100,000 tons each, were designed to fight a war with the Soviet Union.
"They're meant to be able to take and put out a lot of punishment. That doesn't mean they can't be damaged. But they are far less vulnerable than a lot of other warships," he added.
He noted that American sailors frequently train to deal with the type of "asymmetric attack" that might be mounted by a technologically inferior and outgunned adversary.
In March, the Fifth Fleet posted photo and video on its website of sailors practicing a Griffin missile live-fire exercise to prepare against small boat attacks. The U.S. Navy also routinely monitors Iranian naval operations and frequently communicates their counterparts on the other side of the Persian Gulf.
Adm. Fadavi, who also claimed that Iran is in full control of the strategic Strait of Hormuz, the entrance to the Persian Gulf, said Americans have formally demanded a hotline to contact Iranians in case of emergency, but the Guard has turned down the request.
"Nothing [bad] will happen if they leave [the region]," he said.
The rhetoric was delivered as diplomats prepared for a new round of talks this week over a deal to limit Iran's ability to produce nuclear weapons.
Though he cautioned that "overconfidence is a great risk," Mr. Wertheim doubted that the model the Iranians are building would make them any more effective against a real U.S. carrier.
"That doesn't mean we should ignore it," he said. "Iran is about a lot of bluster. ... This gives us a little glimpse into how the Iranian Navy prepares the public and their navy for the event of hostilities, but we shouldn't read too much into it."
The Associated Press contributed. Robert Zullo: firstname.lastname@example.org or 412-263-3909. Twitter: @rczullo.