By Paul Reynolds
World affairs correspondent, BBC News website
Afghanistan has slipped in corruption rankings
The problem of corruption in Afghanistan was highlighted recently when an international survey placed the country as the second most corrupt in the world.
It was beaten only by Somalia.
The survey was carried out by Transparency International, an organisation that tracks corruption worldwide. Afghanistan did so badly it fell from fifth worst to second to bottom.
This is not a new problem in a society once based on clan patronage. What is new is it has become a political obstacle both for the Afghan government and for the countries whose soldiers are dying in its defence, most notably the US and Britain (and not forgetting Canada). It has gathered pace after the corruption uncovered in the presidential election.
President Karzai has now set up his third anti-corruption unit. The first was disbanded when it was revealed its head had been imprisoned on drugs charges in the US.
Not everyone is impressed. "Words are cheap. Deeds are required," said the US ambassador Karl Eikenberry, who has recommended to President Obama that no further US troops be sent until corruption is confronted.
There is no shortage of assessments about the scale of the problem.
In December, US Gen Robert Cone, in charge of training the Afghan army and police, told Reuters: "The final point is corruption, corruption, corruption. It is endemic."
Retired Maj Gen Arnold Fields, the US special inspector general for Afghanistan reconstruction, said in his report last month: "The US government is particularly concerned that corruption puts at risk our investment in the reconstruction of Afghanistan."
And the German Bertelsmann Foundation said in 2006: "The government is imbued by patronage and corruption."
There is no reason to think things have changed.
But how does corruption work in Afghanistan?
Bribery is said to be used to undermine anti-drug efforts
The Bertelsmann Foundation, one of the sources for the conclusions of Transparency International, said: "Corruption is endemic to all state functions (police, judiciary) and is seen as a usual form of business transaction; even ministers were involved in land grabs. Corruption is additionally interlinked with the opium business. Thus, bribery is invested on a massive scale to undermine efforts against the drug economy."
The New York Times reported earlier this year: "Everything seems to be for sale: public offices, access to government services, even a person's freedom."
Contracts, as always in the field of corruption, are a source of actual or alleged wrongdoing.
Integrity Watch Afghanistan, an independent Afghan research organisation, carried out a survey in 2007 that tried to identity the main elements of corruption.
Hamid Karzai has come under pressure to act on corruption
It said: "Corruption networks... have spread in the administration and now constitute a wide and interwoven web of heterogeneous groups that use their positions largely for private or small group gains and effectively block reform.
"A 'bazaar-economy' has developed where every position, favour, and service can be bought and sold. One corrupt practice can be a cause and/or consequence of another corrupt practice, leading to a vicious cycle of self-perpetuation."
At a local level, it listed petty bribery, position buying, nepotism, favouritism and clientelism, and the offering and asking for preferential treatment in areas including the law, land disputes and taxation.
One scam it found was the old one of claiming more than was justified.
"If 100 people were required for a planned workshop, the implementing partner at provincial, district or local level might invite only 20 participants, but demand money for a workshop with 100 participants."
Another example was of favouritism. Integrity Watch Afghanistan said: "An interesting testimony about larger scale corruption at ministry level was provided by an ex-official from a ministry. He reported that in his former career he had observed the disbursement of millions of dollars of aid money based on ethnical, jihadi or kinship boundaries."
As the US special inspector suggested, the influx of billions of dollars of aid money provides rich pickings for officials who want to steer money in certain directions or keep some for themselves.
A report for the World Bank in 2008 said the structure of aid payments was often seen as corrupt in itself.
It said: "Many Afghans consider high pay and overheads for NGOs, contractors, consultants, and advisors to be a form of corruption, irrespective of whether or not the relevant rules were followed in their contracting."
This report, like others, found many people accepted petty bribes were a way of by-passing formalities - some of them, for example car registration, brought in by foreign practice. But it does not end there.
"Based on available survey evidence, most Afghans perceive that bribes must be paid in order to obtain services from the government," the report said.
"Much of the public may be willing to tolerate petty corruption on the part of poorly paid government officials trying to make ends meet, but corruption is commonly perceived to have become organised and entrenched, involving corruption networks with people at all levels involved and those at the top reaping large rewards. "
The perception, or the reality, of people at the top gaining at the expense of people at the bottom is one of the main concerns of foreign governments, which feel this undermines their fight against the Taliban.