It was the deadliest of times in a particularly violent war with daily bombings and firefights. And it was showtime for private security companies. They were in huge demand and the money, with reputed earnings of $1,000 a day, made the job worthwhile despite the ever present danger. Those halcyon days in the aftermath ofthe invasion six years ago have gone for the industry in Iraq, with the presence of foreign forces coming to an end, and the scale of carnage receding a little. The pay rate has fallen steeply and with that the numbers who flock there to make a small fortune, quickly. There are still around 30,000 employed in the field, but only around 5,000 are now Western nationals.
The rules of engagement have also changed. The international private armies are no longer above the law, as they were under Paul Bremer, who as the "proconsul" of occupied Iraq gave the companies immunity from prosecution in local courts.
The catalyst for the security firms being made accountable under Iraqi laws was the Nisoor Square massacre in Baghdad. I was there when guards from the Blackwater firm opened fire on crowded streets, killing more than 17 people and injuring 40. The deaths forced the US administration to investigate. Six Blackwater guards were charged in America, the company lost a lucrative State Department contract and has now changed its name.
Robert Emerson, a security consultant who has worked in Iraq, stated: "The Blackwater shooting totally changed the ballgame in Iraq. When I first went there the lack of regulations was pretty startling and so were the fees some of the companies were charging clients. It is a hugely interesting and lucrative job. But one would think very hard about going there now with the prospect of possibly ending up before an Iraqi court. It would be wrong to equate most of the other contractors with Blackwater. They had a way of doing things which many others found uncomfortable. British companies tended to take a different approach."
The British companies have had a high share of security business in Iraq over the last five years, with contracts worth more than $1bn (£680m) – around one-sixth of the total US budget on private security. Seven UK firms were among the top 20 international companies in earnings in Iraq.
As well as Britons and Americans, the employees are, typically, South Africans, Australians, New Zealanders, Gurkhas, Fijians, and, recently, east Europeans. They have a uniform of wraparound sunglasses, Cargo pants and body armour over dark coloured sweatshirts and, of course, a variety of weaponry.
Most of the guards one meets are reasonable people coping with hazardous jobs. But there are also oddballs. You could have met some at the Mustafa Hotel in Kabul after the fall of the Taliban. An Irish bar had a former boxer as head barman, a dancing Osama bin Laden doll, bullet holes in the ceiling and men who lovingly cradled their guns and wore "shades" at night. The seats for drinking al-fresco were supposedly from Russian MiGs shot down by the Mujahedin. One evening a few of the men "liberated" a chimpanzee from the zoo and propped it up at the bar with an AK-47 rifle. After a while someone thought it prudent to take out the magazine.
Some of the regulars were bad, and possibly mad. One such was Jack Idema, who claimed to be ex-CIA, but was almost certainly a Walter Mitty. That did not stop him running his own "security company" and setting up an unofficial prison. He was later jailed for torturing suspected "terrorists".
When Jason Swindlehurst and Jason Cresswell and their colleagues Alan and Alec were kidnapped in central Baghdad, while on duty guarding IT consultant Peter Moore, also taken, the Nisoor Square killings were still four months away.
Mr Emerson, who was in Iraq at the time, said: "It was a shock. These guys were well-trained, knew what they were doing and still got taken. This shows the danger is always there. What has happened to the two guys is just terrible, let's hope the other three are alright."
Mark Shurben-Browne, a former soldier with the 2nd battalion, the Parachute Regiment, also spent an extensive amount of time in Iraq. "It is not a pleasant thought but they [security guards] need to accept the fact that they may not get back," he said. "They are doing jobs which get paid well, although nothing like some of the figures being bandied around. When I was in Iraq... we had people injured, people killed. But I have got to say it was also quite exciting and I felt I was doing something worthwhile. But... I have four children and I do not take unnecessary risks."
Mr Shurben-Browne helped set up the National Association of Security Professionals, which focuses on the needs of individual security guards rather than companies. A former officer, Col Stuart Tootle, who commanded British troops in Afghanistan, is due to become its president.
"I had always worked for established, reputable companies and I would advise anyone going out to these places to do the same," said Mr Shurben-Browne, a Falklands veteran. "They should make sure that the company has proper back-up and proper insurance. [One] firm refused to pay out money to a widow because she was a common-law wife and not legally married."
Other fronts on the "war on terror" are nothing like as lucrative as Iraq. Andy Bearpark, director general of the British Association of Private Security Companies said: "The average guy is earning £40,000 to £45,000 a year tax-free in Afghanistan, nothing like what people were earning in Iraq. This is very much a different era."
Private security: A global business
Turnover: £62 million in 2005, but probably closer to £100m now.
Number of employees: 1,100 are based in Iraq.
Where they operate: A British company based in London, its staff operate in about 30 countries including China, Afghanistan, Bahrain and Kenya. Most of its work has been in Iraq, where it won a coveted $430m Pentagon contract in 2005 to oversee all private security operations. In 2003, before the contact was awarded, its turnover was only £554,000.
Who do they hire? Former employees of the military, diplomatic and intelligence services and the police.
Control Risks Group
Turnover: At least £80m.
Number of employees: About 700.
Where they operate: Founded in 1975 and has its HQ in London, but now operates in more than 130 countries, more often in consultancy rather than security. Won contracts with the British Government and the American corporations Bechtel and Haliburton in Iraq. In 2003, the company had around 250 personnel working for organisations in Iraq.
Who do they hire? Mostly former members of the military or the police, as well as local nationals.
Number of employees: About 8,000.
Where they operate: In more than 140 countries including Iran, Iraq, Saudi Arabia, Sudan and Indonesia.
Speciality: Small teams who offer protection and advice to executives and diplomats.
Who do they hire? Ex-police officers, soldiers and members of the US Secret Service.
What they charge: Thought to be $1,000 per day for the use of four bodyguards.
Controversies: Two of the company's four bodyguards tasked with looking after IT consultant Peter Moore in Iraq have been confirmed dead.
Turnover: £5.9bn in 2008.
Number of employees: More than 585,000, of which about 1,000 are based in Iraq and 1,200 in Afghanistan.
Where they operate: In more than 110 countries including Iraq, Lebanon and Jamaica.
Speciality: None. Handles security at UK prisons and at Heathrow airport as well as the Wimbledon Tennis Championships. In Iraq and Afghanistan 75 per cent of its staff are locals.
Controversies: Has been accused of driving down wages in countries where it operates and denying workers basic rights.
Number of employees: About 600 worldwide, but it also sub-contracts to local organisations. It's a British company, but its headquarters are in Dubai.
Where they operate: In more than 30 countries including Iraq, Kuwait and Nigeria.
Speciality: Everything from guarding the houses of VIPs to maritime security, asset protection and surveillance. Also engages in post-conflict reconstruction and aid work.
Who do they hire? Former members of the special forces and police officers. Its team has worked with the Prime Minister's office as well as leading technology companies and investment banks.
XE (formerly Blackwater)
Number of employees: About 1,000.
Where they operate: In nine countries, most notably Iraq. Recently rebranded itself as its name was synonymous with the practice of military "outsourcing", in which private contractors take on tasks usually carried out by soldiers.
Speciality: Nowadays, training. The company owns a 7,000 acre facility in North Carolina providing firearms training and weapons and armoured vehicle testing.
Who do they hire? Mainly ex-military: it was founded by Erik Prince, a former Navy Seal.