By Stephen Grey
BBC News, Iraq
The Desert Rats began their six month tour in October
Britain's 7th Armoured Brigade, the Desert Rats, have spent the last four months stationed in the southern Iraqi city of Basra.
During that time, BBC reporter Stephen Grey has been given access to the troops, including the Brigade's most senior commanders.
In a large pretty soulless hotel with long corridors and conference rooms, soldiers are going round and round from meeting to meeting, answering phones or e-mails, just like in any office.
You have to pinch yourself to remember this is Iraq.
The new Brigadier, Patrick Marriott, has one of the bigger rooms with a large rat, made of silver, sitting on his desk.
As commander of the Desert Rats he leads over 4,000 men and is charged with training a recalcitrant police force and helping the Iraqi army maintain security at a critical time for the country's democracy.
The Brigadier has been in Iraq for fewer than 24 hours and as the Desert Rats take control a large car bomb has exploded in Basra city, killing at least 20 people.
"There will be ramifications from last night which I sense could last for the whole of our
Tour," says Brigadier Marriott.
"No-one is quite certain at the moment who is responsible for it and there is a risk here of different factions seeking to blame each other.
"Whereas we're here really to unify the team, as those individual factions are probably here to fraction it. It was bad news last night and it has probably given me an important bit of education early on."
The Brigadier commands his troops through a timetable of meetings - in the morning with some of his closest staff - that is called prayers; and an afternoon conference call, known as the battle group's back brief.
"Good evening and welcome to the conference call. We'll go to the units
first, up to Maysan, Scotch Dragoon Guards"
The radio crackles: "Maysan Battle Group. The town of Al Amara is apparently holding some sort of strike tomorrow. Various phonecalls have been made inviting us not to come into town tomorrow so quite naturally we are going in to conduct our normal daily business.
Back in the conference room, they move on to the next unit: "Basra City, the Highlanders".
"Basra City Battle Groups. Despite having gone into the Hiyaniyah with some
force we were forced to withdraw due to heavy and intense stoning from
large crowds of youths."
When I was first here in 2004 it was all rather different.
British undercover soldiers were rescued from a Basra police station
I stayed downtown in the Marbad Hotel. I could drive around in a taxi, and stop with friends for an ice cream or Muskouf, a famous Iraqi fish dish.
Gradually the situation has got worse. This is now a violent city. Kidnapping, robbery and murder are rife.
And the soldiers avoid going anywhere except in armoured vehicles. It's a strange way of sightseeing.
"We try and be friendly with the kids," say Lance Corporals Brian McIntosh and Alexander Bruce of 1st Battalion the Highlanders Regiment .
"We give them water, give them sweeties, and they just steal stuff from our vehicles, punch us, kick us.
"Every time we drive away, they've got a thing of throwing bricks off us."
Last September, two British Army officers were arrested by Iraqi police and held at a police station in Basra city. It was the day relations between the British army and police force they had created hit rock bottom.
According to army intelligence, elements of the Iraqi police units not only captured the men but also organised campaigns of intimidation, assassinations, and even deadly bomb attacks on British troops.
Lt Colonel Iain Harrison is in charge of security sector reform for the Brigade.
"We'd be kidding ourselves if we tried to leave a decent police force with
some of these bad elements in it.
"Some of it is criminality, some of it is verging on relationships with insurgents which as you can imagine both from a multi-national force point of view and also from a stable and secure Iraqi security forces point of view, those are unacceptable and unsustainable.
"But there are many positive elements of the Iraqi security forces. Our skill will be to use a surgeon's knife to cut out the bad bits and to keep and develop the best parts of it."
The Desert Rats are facing a swirl of rival groups, an all-pervading threat of violence, and their urgent mission is to hand over power to Iraqi forces - while trying to radically reform them at the very same time.
"I read a short while ago in a very good 'lessons learned' pamphlet produced by the Americans that most successful insurgencies, when dealt with in the 20th century, took about nine years, and those that failed took 13 years," says the Brigadier.
"How long will this one take?" I asked. "I don't know. The jury's out."
The second part of Desert Rats' Diary will be broadcast on Thursday, 16 February, at 2000 GMT on BBC Radio 4.
Hear part 1 at Radio 4's Listen again page.