'Fortress Kabul' - The next step?
The latest attack in Afghanistan will lead to a major security review. Heavily protected foreign enclaves may be the result. The idea of an Afghan “green zone", has been predicted before. It may now be closer to becoming a reality.
I know the street where the latest attack took place well. It is close to the site of the former Al Jazeera bureau, where I first worked for this network four years ago.
It seems likely that the Taliban knew there were UN workers staying in the guesthouse and that they were deliberately targeted.
The Taliban does not see the UN as a neutral player. It has direct involvement supporting the election process, and NATO's International Security Force operates under a UN mandate.
Of course, many UN workers are doing humanitarian work that has nothing to do with politics or the military. For example, UN agencies, like the World Food Programme and the UNHCR, are feeding the starving and sheltering the displaced.
The attack is bound to change the way foreigners operate in the Afghan capital and the way they interact with Afghans on a daily basis.
As the security situation has deteriorated, particularly in the south and east of the country, aid workers have found they have been increasingly restricted to the safer parts of the country. For many Kabul is still seen as a place of relative stability.
Despite a number of high-profile attacks, life for the international community in the capital can sometimes seem almost normal. There are shops, restaurants, sports facilities, and even bars. Some foreigners seem to manage energetic social lives in this particular war zone.
Most Taliban attacks in the past have been aimed at Afghan and international forces, foreign embassies and government ministries.
Slowly security has been ramped up. Blast walls ("Hescos", named after the company that makes them) have appeared around the city. More and more roads have been closed.
Despite all this, only on two occasions has there been a mass departure of international personnel. In May 2006 as rioting spread across the city, buildings used by foreigners were among the targets and in January 2008 confidence again tumbled as the five-star Serena Hotel was attacked. That was what the experts call "a complex attack - suicide bombers blowing themselves up at the entrance, and then gunmen heading inside the building.
Exactly the same tactics seem to have been used today.
The latest attack on the guest house, which was followed by rockets fired again at the Serena, is likely to cause much more concern.
The Serena is a Kabul landmark. Right in the centre of the city, it is the only luxury hotel of a truly international standard in the country. The compound, where top level visiting dignitaries stay, will always be seen a potential target.
But international workers have always felt relatively safe in their small, much more discreet guest houses. Many aid agencies, contracting firms and advisers follow the UN lead when it comes to security.
If you are a UN worker in Afghanistan, you cannot just check into any hotel or stay wherever you like.
All premises used for accommodation have to be security cleared by the UN’s own advisers. They make a site visit, checking out the guard force, their weapons and their proficiency. Other requirements have to be met. For example, blast-proof film on the windows, barbed wire on the outer walls. Some owners have also installed safe rooms, blast walls and escape hatches.
Kabul is not yet Baghdad. At the height of the violence in 2005 and 2006, fighters lived and fought in the city - it seemed nowhere was safe, even the heavily-protected "green zone".
In the Afghan capital, the Taliban clearly has its supporters, sympathisers and informers; but each time they plan an attack, the weapons and the fighters need to be infiltrated into the city centre.
This latest attack will lead to a major security review. Heavily protected foreign enclaves may be the result. The idea of "Fortess Kabul", an Afghan “green zone", has been predicted before. It may now be closer to becoming a reality.
The Taliban clearly want to unnerve the international community. Many foreign workers will now, quite literally, not sleep at night.