Wherever you look around the Afghan capital, Kabul, you see blast walls and gun-totting private security guards. They stand in front of fortified compounds for diplomats, NGOs, international companies.

They are also securing convoys - sometimes driving recklessly and causing chaos on the roads. Whether Afghan or foreigner, private security guards are loathed by many in Afghanistan. Some have been involved in deadly accidents where innocent civilians were killed. The latest involved US-based Dyncorps along the Kabul airport road: four Afghan civilians where killed in a car crash, the contractors fled the scene and an angry mob torched the cars and rioted against police.

The behaviour of some of these trigger-happy soldiers for hire has gone so much out of control that Hamid Karzai, the president, recently accused them of "being thieves during the day and terrorists at night".

And now he has tightened the noose around private security companies, or at least so it seems.

Presidential decree

A presidential decree is calling for these companies to be shut down within four months. The Afghan government says that they constitute a parallel force and are a cause of instability. 

By the beginning of next year, the "trouble makers" should be disbanded according to the decree, and foreigners' residency permits will be revoked.

Just a few hours after the decree came out, I was chatting with one of those foreign security contractors -enquiring about whether he is worried he might be out of a job in a few months.

He flatly said "No!" adding that "if we leave, this country will descend into total chaos". He might have a point.

Military justification

There are about 40,000 private security men operating in Afghanistan. More than half work for either the US military or the state department.

The military justifies their need by saying they carry out important tasks, allowing the regular soldiers to concentrate on combat missions. Private security contractors fulfil an array of duties - from securing compounds and military bases, to personnel protection and crucially, securing military convoys along supply routes. It's on these roads where most of the shoot-outs happen and many a time, innocent civilians have been killed.

Now the government says these convoys will be secured with the assistance of the Afghan forces. However, it is a real challenge for a newly born, under-equipped, under-trained force.

These convoys are the preferred targets of the Taliban and other armed militias around the country and I doubt that the US military will accept them putting the fate of supply convoys in the hands of the Afghans. In particular when there is proof that many have been infiltrated. In addition, sections of these roads are under the control of different warlords and it is widely believed that contractors pay them off to ensure safe passage - something neither the US military or the Afghan forces could directly do, in principal at least.

Karzai links questioned

Another reason why the contractor I was speaking to did not believe that the private security companies (PSCs) will shut down is that many of the Afghan companies belong to influential people around the country.

"Will the brother of the president also close down his company," he asked, referring to Ahmed Wali Karzai, half-brother of Hamid Karzai and feared provincial governor of Kandahar.

Allegedly, he has control over some PSCs in the crucial Kandahar area, even though there is no hard proof of his own financial involvement.

The cynics - including many on Capitol Hill - say the new decree is just paving the way for the Karzai family to own security companies once the foreign ones are expelled. Others say this is a pre-election ploy by the president to boost support (parliamentary elections are set for mid-September).

One point everyone agrees on is that these security guards are a destabilising force within the country - a view that is also shared in the latest US congress report.

There is a realization that they have become a liability to the US strategy in Afghanistan (and previously in Iraq). But is expelling them the best way forward?

Doing so could create a security vacuum that the US military - already thinly stretched - will find difficult to fill.