By Kylie Morris BBC correspondent in Kabul

No government can survive if border provinces fail to pass on the customs duties they earn.

Central funds are needed to boost the fledgling national army

In Afghanistan, it's estimated that 12 provinces could net the government of Hamid Karzai more than $500m a year.

But they've only managed so far to come up with a comparatively measly $80m.

It's not difficult to see where the money is going:

• Provincial pockets
• Private armies
• Buying favours
• Building local empires

High risk

The government has pleaded with the international military force which safeguards Kabul to extend its reach and provide stability and security in the provinces, thereby providing the government with a platform to exercise its authority.

But the contributing nations aren't prepared to make that commitment.

Karzai risks being shown up as a weak president

This is having a massively detrimental effect on Hamid Karzai's government.

He says he knows the people are becoming disillusioned and has warned that peace can't survive under such conditions.

In fact, the president has said that if things don't change in the next few months, he'll call another grand assembly or loya jirga.

Then, the people can choose a new government.

It's a high-risk strategy.

The governors may be holding Afghanistan's economy hostage. But in the past, Hamid Karzai's commands and requests have fallen on deaf ears.

He sacked more than 20 provincial officials in November who he determined to be corrupt. But the majority of them are still in their jobs.

This time though he must succeed, otherwise it would show his weakness as a leader, and demonstrate to Afghanistan's unelected power brokers that the central government can't touch them.