America - Andrew Stephen on the mercenaries in Iraq

The US military now puts machine-guns into the hands of mercenaries, who could hardly have a more "m

In the US, the vocabulary of the Iraq war simply does not permit the use of the word "mercenaries". Most Americans do not realise that the second-biggest military force in Iraq - more than twice that of the UK - consists of mercenaries, recruited by the US government both here and in other countries, including Iraq itself. When four such mercenaries were killed and their bodies butchered at the end of last month, the men were invariably described in the media here as "US civilian contractors", though they were armed men guarding a US military convoy.

There are now 20,000 such mercenaries in Iraq. The number is expected to grow soon to 30,000, and they can be paid as much as $1,500 a day. They are there, in the words of the Washington Post, to perform tasks "too messy, too dull and too questionable" for the military itself to undertake. The Pentagon says it does not have enough specially trained troops or Iraqi policemen to perform guard duties. Senator John Warner, chairman of the Senate armed services committee, describes the private military recruits as "our silent partner". Rather than using highly trained US soldiers for the task, the security for L Paul Bremer, the chief US envoy in Iraq, is - astonishingly - provided by a private "security" firm. The "green zone" in Baghdad, where the US command is bunkered down, is also guarded by private soldiers, as are 15 or so other US regional headquarters.

Because the 20,000 guards theoretically perform only security duties, which in many cases escalate into deadly gunfights, the US authorities can claim that they are not, in fact, mercenaries. But the relevant international convention defines a mercenary as someone who "is specially recruited locally or abroad in order to fight in an armed conflict . . . [and] is motivated to take part in the hostilities essentially by the desire for private gain [and is paid] substantially in excess of that promised or paid to combatants of similar rank and functions in the armed forces of that party".

Two floors of the Palestine Hotel - guarded by Gurkha mercenaries - have been taken over by Kellogg Brown & Root. This is a subsidiary of Halliburton, the company that Vice-President Dick Cheney used to head. The four mutilated soldiers were recruited by Blackwater USA, which consists of the Blackwater Training Centre, Blackwater Target Systems, Blackwater Security Consulting, Blackwater Canine and Blackwater Air. Its internet clearing house for mercenaries invites people to "come to Blackwater, where the professionals train". In Najaf, eight commandos from Blackwater repulsed attacks by the militia of Moqtada al-Sadr, firing thousands of rounds before calling in Blackwater helicopters to their aid.

Orders proposed for the mercenaries, but still to be adopted, are that they first shout a warning, then "shove" miscreants, then show their weapons, and then finally shoot. In the event of a chemical or biological attack, the mercenaries are ordered by a government document to "keep the area near the guard post clear of people", though everyone involved acknowledges that the guards are not subject to US military discipline and can abandon their posts if they wish. Indeed, most of the mercenaries make their own rules: stories are told of how some drink around hotel swimming pools, weapons at their feet. The manager of one hotel asked the mercenaries to hide their weapons when they left the hotel, but they ignored him.

Mercenaries have been recruited from Chile and South Africa, where, it turns out, some were in the apartheid-era armed forces. They could end up costing as much as a quarter of the $18bn budgeted for reconstruction, compared with estimates of 10 per cent not long ago. US soldiers are openly grumbling that the mercenaries are paid between $500 and $1,500 a day. Because of the rush in recruitment, there is often little time to check the credentials of applicants. There is no central oversight for the companies, nor any uniform rules of engagement. Some mercenaries complain of being thrust into dangerous situations with inadequate equipment and body armour, but the pay rates make recruits still eager to go to Iraq.

The private companies do not just fly helicopters, guard bases and provide reconnaissance for the US forces, they also have contracts to maintain an array of weapons systems, including the B-2 bomber, F-117 stealth fighter, Apache helicopter and unmanned spy planes. For-profit military companies have an estimated $100bn in worldwide business every year, with much of the profit going to conglomerates such as Halliburton, DynCorp, Lockheed Martin and Raytheon, all of which are heavily involved in Iraq. The Steele Foundation, the world's fifth-largest security firm, has 500 mercenaries in Iraq. A third are westerners, and the rest Iraqis. Global Risk Strategies, based in Middlesex, has as many as 1,500 private guards in Iraq.

The mercenaries are recruited for other parts of the world, too, and were supposedly bodyguards for Jean-Bertrand Aristide in Haiti, though they did not stop the US spiriting Aristide away to the Central African Republic. The mercenary companies say that 94 of their employees have been killed since the beginning of last year, with 1,164 injuries. There are suspicions here that statistics for US military deaths and casualties are being kept down artificially by not including mercenary deaths and injuries. The worsening of the situation in Iraq has led some private companies to work more with each other. Each firm amounts to an individual battalion, and in Iraq they are coming together to form the largest security organisation in the world.

An expert at the Brookings Institution says that the US military has long held a doctrine that it "does not turn over mission-critical functions to private contractors". Yet in Iraq it puts machine-guns into the hands of mercenaries, allows them to fight fiercely with local militias, and relies on them to keep Bremer out of harm's way. There could hardly be a more "mission-critical" operation for these "civilian contractors".