The disgusting and heartbreaking photos published last week in the German media, and more recently in Rolling Stone magazine, are finally bringing the grisly truth about the war in Afghanistan to a wider public. All the PR about this war being about democracy and human rights melts into thin air with the pictures of US soldiers posing with the dead and mutilated bodies of innocent Afghan civilians.

I must report that Afghans do not believe this to be a story of a few rogue soldiers. We believe that the brutal actions of these "kill teams" reveal the aggression and racism which is part and parcel of the entire military occupation. While these photos are new, the murder of innocents is not. Such crimes have sparked many protests in Afghanistan and have sharply raised anti-American sentiment among ordinary Afghans.

I am not surprised that the mainstream media in the US has been reluctant to publish these images of the soldiers who made sport out of murdering Afghans. General Petraeus, now in charge of the American-led occupation, is said to place great importance on the "information war" for public opinion – and there is a concerted effort to keep the reality of Afghanistan out of sight in the US.

Last week my initial application for a US entry visa was turned down, and so my book tour was delayed while supporters demanded my right to enter the country. The American government was pressed to relent and allow my visit to go ahead. Ultimately it too will be unable to block out the truth about the war in Afghanistan.

The "kill team" images will come as a shock to many outside Afghanistan but not to us. We have seen countless incidents of American and Nato forces killing innocent people like birds. For instance, they recently killed nine children in Kunar Province who were collecting firewood. In February this year they killed 65 innocent villagers, most of them women and children. In this case, as in many others, Nato claimed that they had only killed insurgents, even though local authorities acknowledged that the victims were civilians. To prevent the facts coming out they even arrested two journalists from al-Jazeera who attempted to visit and report from the site of the massacre.

Successive US officials have said that they will safeguard civilians and that they will be more careful, but in fact they are only more careful in their efforts to cover up their crimes and suppress reporting of them. The US and Nato, along with the office of the UN's assistance mission in Afghanistan, usually give statistics about civilian deaths that underestimate the numbers. The reality is that President Obama's so-called surge has only led to a surge of violence from all sides, and civilian deaths have increased.

The occupying armies have tried to buy off the families of their victims, offering $2,000 for each one killed. Afghans' lives are cheap for the US and Nato, but no matter how much they offer, we don't want their blood money.

Once you know all this, and once you have seen the "kill team" photos, you will understand more clearly why Afghans have turned against this occupation. The Karzai regime is more hated than ever: it only rules through intimidation, corruption, and with the help of the occupying armies. Afghans deserve much better than this.

However, this does not mean more Afghans are supporting the reactionary so-called resistance of the Taliban. Instead we are seeing the growth, under very difficult conditions, of another resistance led by students, women and the ordinary poor people of Afghanistan. They are taking to the streets to protest against the massacre of civilians and to demand an end to the war. Demonstrations like this were recently held in Kabul, Marzar-e-Sharif, Jalalabad and Farah.

This resistance is inspired by the movements in other countries like Egypt and Tunisia – we want to see "people power" in Afghanistan as well. And we need the support and solidarity of people in the Nato countries.

Many new voices are speaking up against this expensive and hypocritical war in Afghanistan, including soldiers from the Nato armies. When I last visited the UK I had the honour of meeting Joe Glenton, a conscientious objector who spent months in jail for his resistance to the war in Afghanistan. Of his time in prison, Glenton said: "In the current climate I consider it a badge of honour to have served a prison sentence."

So while the world looks in horror at the "kill team" photographs, Joe Glenton's courage and humanity is an important reminder that the war in Afghanistan need not last forever.