American military operations for a major conventional war with Iran could be implemented any day. They extend far beyond targeting suspect WMD facilities and will enable President Bush to destroy Iran's military, political and economic infrastructure overnight using conventional weapons.

British military sources told the New Statesman, on condition of anonymity, that "the US military switched its whole focus to Iran" as soon as Saddam Hussein was kicked out of Baghdad. It continued this strategy, even though it had American infantry bogged down in fighting the insurgency in Iraq.

The US army, navy, air force and marines have all prepared battle plans and spent four years building bases and training for "Operation Iranian Freedom". Admiral Fallon, the new head of US Central Command, has inherited computerised plans under the name TIRANNT (Theatre Iran Near Term).

The Bush administration has made much of sending a second aircraft carrier to the Gulf. But it is a tiny part of the preparations. Post 9/11, the US navy can put six carriers into battle at a month's notice. Two carriers in the region, the USS John C Stennis and the USS Dwight D Eisenhower, could quickly be joined by three more now at sea: USS Ronald Reagan, USS Harry S Truman and USS Theodore Roosevelt, as well as by USS Nimitz. Each carrier force includes hundreds of cruise missiles.

Then there are the marines, who are not tied down fighting in Iraq. Several marine forces are assembling, each with its own aircraft carrier. These carrier forces can each conduct a version of the D-Day landings. They come with landing craft, tanks, jump-jets, thousands of troops and, yes, hundreds more cruise missiles. Their task is to destroy Iranian forces able to attack oil tankers and to secure oilfields and installations. They have trained for this mission since the Iranian revolution of 1979.

Today, marines have the USS Boxer and USS Bataan carrier forces in the Gulf and probably also the USS Kearsarge and USS Bonhomme Richard. Three others, the USS Peleliu, USS Wasp and USS Iwo Jima, are ready to join them. Earlier this year, HQ staff to manage these forces were moved from Virginia to Bahrain.

Vice-President Dick Cheney has had something of a love affair with the US marines, and this may reach its culmination in the fishing villages along Iran's Gulf coast. Marine generals hold the top jobs at Nato, in the Pentagon and are in charge of all nuclear weapons. No marine has held any of these posts before.

Traditionally, the top nuclear job went either to a commander of the navy's Trident submarines or of the air force's bombers and missiles. Today, all these forces follow the orders of a marine, General James Cartwright, and are integrated into a "Global Strike" plan which places strategic forces on permanent 12-hour readiness.

The only public discussion of this plan has been by the American analysts Bill Arkin and Hans Kristensen, who have focused on the possible use of atomic weapons. These concerns are justified, but ignore how forces can be used in conventional war.

Any US general planning to attack Iran can now assume that at least 10,000 targets can be hit in a single raid, with warplanes flying from the US or Diego Garcia. In the past year, unlimited funding for military technology has taken "smart bombs" to a new level.

New "bunker-busting" conventional bombs weigh only 250lb. According to Boeing, the GBU-39 small-diameter bomb "quadruples" the firepower of US warplanes, compared to those in use even as recently as 2003. A single stealth or B-52 bomber can now attack between 150 and 300 individual points to within a metre of accuracy using the global positioning system.

With little military effort, the US air force can hit the last-known position of Iranian military units, political leaders and supposed sites of weapons of mass destruction. One can be sure that, if war comes, George Bush will not want to stand accused of using too little force and allowing Iran to fight back.

"Global Strike" means that, without any obvious signal, what was done to Serbia and Lebanon can be done overnight to the whole of Iran. We, and probably the Iranians, would not know about it until after the bombs fell. Forces that hide will suffer the fate of Saddam's armies, once their positions are known.

The whole of Iran is now less than an hour's flying time from some American base or carrier. Sources in the region as well as trade journals confirm that the US has built three bases in Azerbaijan that could be transit points for troops and with facilities equal to its best in Europe.

Most of the Iranian army is positioned along the border with Iraq, facing US army missiles that can reach 150km over the border. But it is in the flat, sandy oilfields east and south of Basra where the temptation will be to launch a tank attack and hope that a disaffected population will be grateful.

The regime in Tehran has already complained of US- and UK-inspired terror attacks in several Iranian regions where the population opposes the ayatollahs' fanatical policies. Such reports corroborate the American journalist Seymour Hersh's claim that the US military is already engaged in a low-level war with Iran. The fighting is most intense in the Kurdish north where Iran has been firing artillery into Iraq. The US and Iran are already engaged in a low-level proxy war across the Iran-Iraq border.

And, once again, the neo-cons at the American Enterprise Institute have a plan for a peaceful settlement: this time it is for a federal Iran. Officially, Michael Ledeen, the AEI plan's sponsor, has been ostracised by the White House. However, two years ago, the Congress of Iranian Nationalities for a Federal Iran had its inaugural meeting in London.

We should not underestimate the Bush administration's ability to convince itself that an "Iran of the regions" will emerge from a post-rubble Iran.

Dan Plesch is a research associate at the School of Oriental and African Studies

Articles from this issue on Iran
This, Mr President, is how wars start by Andrew Stephen
Sheer incompetence could be the trigger.

We are asking the wrong questions of Iran by Rageh Omaar
Rageh Omaar finds a country more complex than most in the west have ever realised