Anthony Sampson: Mercenaries are unaccountable - which is why governments like to employ them

Parts of the world are looking like 14th-century Europe, when kings had to pay private armies to protect them

As the fighting escalates in Iraq, we have to be more concerned about the use of mercenary armies - oops, I mean private military firms - which have taken over part of the role of the allied forces.

As the fighting escalates in Iraq, we have to be more concerned about the use of mercenary armies - oops, I mean private military firms - which have taken over part of the role of the allied forces.

At a time when the British and American armies are stretched close to their limits, in operations which need to be strictly controlled, are we allowing private armies and contractors too much power? Is war, like so many other industries, gradually being privatised?

It's worth looking back at the development of mercenaries, which have always had a sinister image as "the dogs of war". They came into the limelight nine years ago in Africa, where the weak government in Sierra Leone hired the shadowy British company Sandline to defeat the rebel army - which it achieved in two weeks with the help of helicopter gunships.

Since then British mercenary companies have proliferated through Africa, forming and re-forming and changing their names to baffle investigators, but showing signs of strong financial links with control from London and South Africa. Many of the soldiers are ex-members of the Afrikaner military or police with connections with the old apartheid regime, and a dubious record of civilised behaviour.

The Pretoria government of President Mbeki has effectively disowned them; when earlier this year mercenaries were arrested and imprisoned in Zimbabwe, on their way to mount a coup in Equatorial Guinea, the Zimbabwe government was apparently acting on a tip-off from Pretoria.

Their leader Simon Mann, a well-connected buccaneer from Eton and the Scots Guards - who had been a co-founder of Sandline - is trying to use his influence in London to achieve his release; the outcome may reveal something about how far he enjoys discreet backing from the British Government.

But the role of the mercenary companies has spread far beyond Africa, and for the past year it has been Iraq which has provided by far their biggest opportunity for profits.

Most Western companies employed private security companies, and the American proconsul Paul Bremer was himself protected by guards hired by the American firm Blackwater.

The American mercenaries had a dangerously ambiguous status, or lack of status. Officially the army had no obligation to protect them, yet it felt obliged to come to their rescue when necessary. When four Blackwater soldiers rashly arrived at the dangerous city of Fallujah, and were hideously murdered and mutilated by the Iraqi rebels, the much-publicised atrocity encouraged American marines to take revenge, rampaging into the city centre, and killing hundreds of Iraqis, including many innocent civilians.

Since the interim Iraqi government took over in July, the role of mercenaries has increased rather than diminished, and they received new recognition when a contract worth nearly $300m was signed with Tim Spicer, the head of the British company Aegis - a co-founder with Simon Mann of Sandline (which officially went out of business in April).

Other parts of the world were also becoming happy hunting grounds for private armies, whether in the Middle East, Africa or Central Asia, as big corporations felt more need of protection in the wake of 11 September, which weak governments or failed states could not provide.

Are we regressing to an earlier age, before nation-states had acquired their disciplined armies with a monopoly of force, and both governments and business relied on mercenaries for their survival? Parts of the world are looking like 14th-century Europe, when kings and city-states had to pay private armies to protect them; and the English mercenary Sir John Hawkwood marched his "white company" through the continent, selling his services to popes and potentates in return for short-lived security.

So are we heading towards the privatising of wars, whose outcomes will be decided by whoever can pay most to freebooting soldiers beyond the control of governments?

Of course, the mercenaries themselves see it quite differently. They insist they are responding to the urgent global need for security. And one of them, John Davidson, the founder-manager of Rubicon International, has now launched a spirited defence on the internet.

As a former officer in the British Special Forces, Davidson claims that private firms are continuing their proud tradition in Iraq, "the most dangerous place on the planet today". "It is strange that within a month of leaving the British forces as heroes," he writes, "we are now classed in the media as 'dogs of war' or 'mercenaries making a killing in Iraq'."

Many of the British security teams in Iraq, he insists, have won the hearts and minds of Iraqis, as the American marines could not by the use of force. "The security companies have become the buffer between the military and the locals to great effect."

And he concludes: "I believe the security industry has the most important role in Iraq, and this will become more apparent in the next six months."

Davidson's arguments are quite persuasive, as the American army faces more dangerous confrontations with rebel forces in Iraq today. Both the American and British armies are clearly undermanned for the task, and recruitment becomes increasingly difficult, and mercenaries and contractors can rapidly fill the gap.

Many British diplomats and generals defend the use of mercenaries on wider grounds, and across the world. They can perform peacekeeping jobs which national armies cannot do, protecting both human lives and corporate property in lawless countries which cannot provide their own security.

The rise of private armies has its own obvious logic in a privatised world, where national armies are increasingly undermanned and under growing pressure, and business corporations are setting the pace. And Jack Straw, back in 2002, officially endorsed the "outsourcing" of some military tasks to private companies.

But the hazards are now much more apparent. Many private companies have shown themselves unaccountable to any government, while many mercenaries include men who owe no allegiance to any country, or to any recognised laws. Their unaccountability may be their main attraction to their clients, but it threatens to undermine the basic discipline on which real peacekeeping depends.

When major governments surrender their monopoly of force to mercenaries, in countries where law and order are fragile, they are introducing a new danger to the "war on terrorism". They may see themselves as fighting "unlawful combatants" - as the Americans define the prisoners in Guantanamo Bay. But they are recruiting their own unlawful combatants to the struggle, and threatening to extend the areas of chaos which provide the seedbeds of terrorism.