CHINA:Much of Iran's territory is now within range of air and missile weapons, writes Tom Clonan
Whatever its actual intentions, the US military has deployed significant air and naval assets to the Persian Gulf in recent days. The navy's USS Dwight D Eisenhower carrier strike group is already on station in the Arabian Sea - bringing much of Iran's airspace and territory within range of US air and missile weapons.
The US navy is now deploying a second carrier strike group - the USS John C Stennis - to the Persian Gulf. The combination will bring more than 170 additional US military aircraft within striking range of Iranian naval, air and missile installations in the coming days. In addition to this dramatic air and naval build-up, the US has deployed at least two additional Los Angeles class attack submarines to the area.
Significantly, this naval presence consists of at least 10 surface vessels, including aircraft carriers, guided missile cruisers and guided missile destroyers capable of delivering large numbers of Tomahawk cruise missiles and Trident fleet ballistic missiles to potential targets anywhere in Iran. The fleet's attack submarines would also be capable of delivering waves of Tomahawk missiles to potential targets throughout Iran.
There has been no parallel concentration of ground forces by the US in the region, suggesting that an invasion is unlikely. This is not surprising given the overstretch being experienced by US infantry and marine corps commanders in Iraq and elsewhere.
The deployment is also consistent with statements in recent days by President George Bush that the US does not intend to deploy its forces in Iran - irrespective of any actions by alleged Iranian agent provocateurs within Iraq or as a consequence of its nuclear programme.
However, and perhaps ominously, Mr Bush has said all other options remain on the table on curbing Iran's nuclear ambitions and a burgeoning Iranian/Shia regional influence that extends from the Persian Gulf, through Iraq and Syria to Lebanon and the Mediterranean.
Aside from diplomatic broadsides, the Iranians are not in a position to provide direct deterrence to the US naval presence. The Iranian airforce consists of a small number of outdated Soviet-style MiG-27s and MiG-29s along with approximately one dozen F-14 fighter jets and some recently acquired SU-25 Russian manufactured "Frogfoot" fighters. These would be no match for the hundreds of state-of-the-art US F/A 18s and F-16 fighter jets.
The US and Israel are increasingly uneasy about Iran's rapidly developing nuclear facilities at Natanz, Isfahan and Arak. Indeed, the precise make-up of the US deployment in recent days consists of a perfectly matched suite of weapons systems tailor-made to neutralise such deeply buried and reinforced subterranean targets.
Both carrier strike groups carry squadrons of F/A-18 fighter aircraft especially equipped with JDAM BLU-109 and BLU-119 "Bunker Buster" guided bombs along with the extra fuel cells necessary - in theory - to make the return flights from the carrier groups in the Gulf to any of the Iranian nuclear sites.
The Iranians would be practically defenceless in the event of such strikes. Iranian anti-missile air defences and technologies are based on outdated and unsophisticated Chinese, North Korean and older Soviet designs.
In retaliation, the Iranians would have the capability to close the Strait of Hormuz more or less indefinitely, disrupting oil production and oil tanker traffic, thus effectively closing off 20 per cent of the world's oil supplies. Many in the defence and intelligence community also believe such an attack would lead to a dramatic and unprecedented increase in international terrorism from Islamic resistance groups on a scale that would dwarf previous campaigns.
However, senior sources in the US military are beginning to voice concerns about a possible unilateral and pre-emptive tactical nuclear strike by Israel on Iran's nascent nuclear facilities.
One senior US military source said such an attack would plan to put Iran's nuclear facilities "verifiably beyond use" - by radioactively contaminating the Natanz, Arak and Isfahan sites, thus preventing any future redevelopment by Iran.
These same sources also speak of US air and missile strikes on Iran as being "inevitable, not just possible". As the sabres rattle, the stakes in the Persian Gulf appear to be getting higher and higher.
Dr Tom Clonan is the Irish Times security analyst.