Foreign friends or foes? America must fight the Taliban's propaganda as well as its combatants. Photograph: US Department of Defense

For the last two months, US President Barack Obama has wrestled with the quandary of whether to send more troops to Afghanistan, as his commander Stanley McChrystal requested in his leaked secret report.

Many Americans have seen his endless discussions in the Situation Room – seven war councils to date – as an inability to make decisions. Others fear that if he agrees to send more force – on top of the 21,000 he already agreed to send earlier this year, making a total of 68,000 US troops – that the US will be digging itself into a Vietnam-like quagmire.

From my own experience on the ground, making repeated visits to Afghanistan including three trips this year, sending more troops has only led to more fighting and spread Taliban influence. Each time I go I can travel to fewer places. Over the last year the number of troops has doubled. Yet the Taliban have expanded from their traditional strongholds of the south and east into the north and west. They have successfully convinced many Afghans to see the conflict as a nationalist issue – yet another foreign invader.

The real issue is not troop numbers. As the farce of this year's presidential election so starkly highlighted, Afghanistan’s key problem is the lack of a credible government. While most Afghans don’t want the Taliban back, on the other side all they see from the government of Hamid Karzai is corruption and a police force demanding bribes.

As Ashraf Ghani, Afghanistan’s former finance minister, explains: “Afghans are caught between a predatory insurgency and a predatory government and their main focus now is on surviving.”

In Kabul earlier this year I met a man who brought home this dilemma. For the last 15 years, Ahmed Bachar ran an orphanage in Logar looking after children whose parents have been killed or mutilated in the war that has gone on for three decades. Bachar made sure they got to school, had a meal and somewhere to sleep every night.

After the ouster of the Taliban regime in November 2001, he started receiving international aid money. With this he arranged a proper building, books, clothes and occasionally even balloons and kites for the children to play with. One night last summer, masked Taliban came to his house and accused him of working with foreigners. They threatened to kill him if he did not stop.

“I was terrified,” he said. “But I look after around 200 children aged from five to 16 and didn’t know what would happen to them if I stopped.”

So he went to the mosque and told the local community. It was a risk: among those gathered for prayers were local shopkeepers and farmers who he knew donned masks at night and joined the Taliban patrolling the streets. The people beseeched him to stay. “We need you to look after our children,” they said. “We will talk to the Taliban and ask them to let you continue.”

A few nights later the Taliban again dragged him out of his house and told him he could stay as long as he broke off all association with foreigners.

Bachar was not convinced. He fled to Kabul where I met him in hiding with his five daughters and two sons. “Maybe 80 percent they leave me alone, but 20 percent chance they kill me,” he said. “The problem is, I cannot trust the government forces to protect me. The police only want bribes from us. We are caught between the two.”

Tears spilled from his eyes as he told me how guilty he felt. “I have sacrificed the orphans for the safety of my own children,” he said. “Who will care for them now?”

Bachar’s case, in a town just an hour’s drive from the capital, is typical. NATO troops can defeat the Taliban in direct battle, but what the Taliban do is control the terrain psychologically.

Whether or not President Obama ends up sending more troops, his real challenge is to ensure the Karzai government offers something to people like Bachar.

This article appears as part of the first in a series of special reports produced with Carnegie Europe, the pan-European foreign policy forum of the Carnegie Endowment for International Peace, to raise the debate in Europe on Afghanistan and the broader crisis gripping south Asia.