

The US military has been embarrassed by footage broadcast on al-Jazeera television which shows soldiers and a chaplain discussing how to convert Afghans to Christianity.

This brought a predictable reaction in Afghanistan, where former prime minister Ahmad Shah Ahmadzai told Reuters news agency: "We consider this act as a direct attack on our religion that will arouse Afghans' emotions to take actions against them."

The US miltary claims the footage was shown out of context and al-Jazeera insists it was not. The troops in the video seem aware that Centcom's General Order Number 1 forbids them from proselytising while on active duty but one says there are ways around this – for example, by presenting people with Bibles as "gifts".

It is not the first time the US military has got into hot water over religion. Lt Gen William Boykin, an evangelical Christian and warrior against Satan, caused a stir by recalling how a Muslim fighter in Somalia had claimed to have the protection of Allah against US forces.

"Well you know what I knew, that my God was bigger than his," Boykin said. "I knew that my God was a real God, and his was an idol."

The military orders are there for a reason: bringing Jesus into the Afghan conflict is politically stupid and it reinforces the claims of bin Laden and others that western forces are engaged in a "crusade".

Equally, I can't imagine the US military would be very pleased if Afghans started turning up at their bases with copies of the Qur'an and wanting to discuss its contents.

That said, though, al-Jazeera seems to have missed a more important point about free speech. It is a crime in Afghanistan to try to convert people away from Islam - and it shouldn't be.

Freedom of speech requires that everyone should be allowed to express their views, and this includes trying to persuade others to agree with them.

Setting aside the miliary aspects of this, if a private citizen of any nationality wishes to go to Afghanistan and talk about Christianity, why should they be prevented from doing so? It may be a foolhardy thing to do, but who has the right to stop them?